Flu vaccination programme 2025 to 2026: information for healthcare practitioners

Question 1

Influenza vaccination programme 2025 to 2026

Accepted Answer

This document contains information about the influenza vaccination programme 2025 to 2026, the inactivated influenza vaccines (IIV) and the live attenuated influenza vaccine (LAIV). It will be updated with any new information that becomes available as the flu vaccination season progresses. The final section of this document provides additional information and advice on common issues that may be encountered whilst delivering the flu immunisation programme.

It is recommended that you read the letters and resources available on the UK Health Security Agency (UKHSA) annual flu programme webpage. These webpages should be regularly checked as any further information that becomes available about the flu vaccination programme will be published there.

Further programme updates may also be reported in Vaccine Update, so subscribe to Vaccine Update using the link for new subscribers if you have not already done so.

Background

The seasonal influenza vaccination programme was introduced in England during the late 1960s to protect those in clinical risk groups. These groups were found to be at higher risk of influenza-associated morbidity and mortality. Since then, the programme has been extended to include all those aged 65 years and over (in the year 2000), pregnant women (in 2010), healthy children (2013) and those with a body mass index (BMI) of 40 or more (2016).

Studies commissioned by the Joint Committee on Vaccination and Immunisation (JCVI) (1) suggested that, despite the high cost, extending the flu vaccination programme to all children would be highly likely to be cost-effective and well below the established cost-effectiveness threshold when indirect protection to the whole population is considered, particularly over the longer term. This is because offering influenza vaccine to healthy children not only provides individual protection to the child, it also reduces transmission across all age groups to lessen levels of flu activity overall and reduces the burden of flu across the population. Pebody and others (2, 3) have reported reductions in GP consultations for influenza-like illness, swab positivity in primary care, laboratory-confirmed hospitalisations and percentage of respiratory emergency-department attendances.

The flu vaccination programme for all children, not just those in risk groups, was recommended in 2012 by JCVI (4) and has been phased in over a number of years beginning in 2013 with additional age groups being added each year. Since the 2023 to 2024 flu vaccination season this has included the full roll-out of the programme with all school-aged children from Reception to Year 11 being offered vaccination, as well as 2- and 3-year-olds (although children up to and including Year 11 were also offered flu vaccine in the 2021 to 2022 flu season).

2025 to 2026 flu programme summary

Seasonal flu vaccination is a critically important public health intervention to reduce morbidity and mortality in those most at risk, including older people, pregnant women and those in clinical risk groups. It helps the health and social care system manage winter pressures by helping to reduce demand for GP consultations and likelihood of hospitalisation. Vaccinating health and care workers also plays an important role in helping to prevent transmission of flu, protecting themselves and those that they care for.

A comprehensive list of the groups included in the national immunisation programme for the 2025 to 2026 flu season in England are described in the National flu immunisation programme 2025 to 2026 letter and in the Vaccine eligibility section below.

The start of the adult programme for 2025 to 2026 will be from 1 October 2025 with the majority of vaccinations to be completed by the end of November. There are some exceptions to this later start date. Vaccination of pregnant women should continue to be offered from 1 September. The children’s programme should also continue to start from 1 September or as soon as delivery and supply of vaccine allows. See Timing of vaccination section or as soon as delivery and supply of vaccine allows.

Other changes to the 2025 to 2026 flu vaccine programme are that:

all the vaccines recommended for use in 2025 to 2026 flu vaccination season will be trivalent influenza vaccines, containing 2 influenza A strains and one influenza B strain
the recombinant influenza vaccine (IIVr) will be available for the 2025 to 2026 flu vaccination season (after not being available for the 2024 to 2025 flu vaccination programme)
the adjuvanted inactivated influenza vaccine (aIIV), previously available for those aged 65 years and over, is now licensed from age 50 years and over

Question 2

Main documentation

Accepted Answer

The requirements of the influenza vaccination programme are set out in the following main documents:

The National flu immunisation programme letters provide information to support the successful implementation of the programme.
The GP enhanced service specifications for the seasonal influenza vaccination programme and childhood seasonal influenza vaccination are published on the NHS GP contract web page.
Seasonal influenza PGDs and the National flu protocol from UKHSA.
The advanced service specifications for community pharmacy seasonal influenza vaccination and childhood seasonal influenza vaccination are published on the Community pharmacy seasonal influenza vaccine service webpage.
The Green Book Influenza chapter provides information on influenza disease, epidemiology, the vaccines and the vaccination programme.

Additional resources to support the implementation of the programme include template letters, leaflets, posters, a training slide set and a flu e-learning programme, all of which can be found on the Annual flu programme page of the GOV.UK website.

Question 3

Influenza

Accepted Answer

Detailed information on influenza infection, epidemiology and the vaccination programme is included in the Green Book Influenza chapter and at the flu page of NHS.UK.

Influenza is a highly infectious, acute viral respiratory tract infection that has a usual incubation period of one to 3 days. Patients can experience sudden onset of symptoms such as dry cough, headache, fever and extreme fatigue.

There are 3 types of influenza virus that affect humans: types A, B and C. Types A and B are responsible for most disease.

Influenza is spread by droplets, aerosol or through direct contact with the respiratory secretions of someone with the infection. For otherwise healthy individuals, it is an unpleasant but usually self-limiting disease with recovery occurring within 2 to 7 days.

However, more serious illness may occur in children under 5 years, pregnant women, those aged over 65 years and those with underlying health conditions. These groups are at higher risk of developing severe complications such as bronchitis, secondary bacterial pneumonia, or otitis media in children and complications in pregnancy including prematurity and smaller birth weight.

Influenza vaccination programme

The purpose of the influenza vaccination programme is to protect those most at risk of developing severe disease or complications or from dying if they develop the infection.

Individuals not eligible for vaccination will benefit from reduced circulation in the community gained through the childhood flu vaccination programme and infants under the age of 6 months should benefit from passive protection if their mother received the vaccine during pregnancy.

The specific vaccines recommended in the National flu immunisation programme plan 2025 to 2026 should be used to protect individuals and enable providers to receive payment for the administration and reimbursement costs.

Legal frameworks to supply and/or administer influenza vaccines

All vaccines are classified as prescription-only medicines (POMs). This means that they are subject to legal restrictions and, in order to give them, there needs to be an appropriate legal framework in place before they can be supplied and/or administered to eligible people. Any person who supplies and administers a vaccine must have a legal authority to do so. This legal authority may be in the form of a written patient-specific prescription, a Patient Specific Direction (PSD), a Patient Group Direction (PGD) or another process such as a Written Instruction or a Protocol.

Patient Group Direction

UKHSA develop and publish a Patient Group Direction (PGD) template for inactivated flu vaccine and a Patient Group Direction (PGD) template for live attenuated influenza vaccine (LAIV) to support the administration of influenza vaccines each year. The PGDs are not legally valid until they have had the relevant organisational authorisation from an appropriate authorising person in Section 2 of the PGD.

National protocol

Since 2020, regulation 247A of the Human Medicines Regulations has allowed for a national protocol authorised by ministers to be used for the supply and administration of influenza vaccines. This national protocol, developed by UKHSA, allows specified classes of people, which need not be limited to registered healthcare professionals, to administer the injectable inactivated influenza vaccines. The protocol may be followed wholly by a specified registered healthcare professional from patient assessment through to post-vaccination. Alternatively, multiple healthcare workers may undertake stages in the patient vaccination pathway in accordance with the protocol. The protocol requires a registered healthcare professional to undertake the assessment of each patient and consent for vaccination. Where multiple person models are used, the service provider or contractor must ensure that all elements of the protocol are complied with in the provision of vaccination to each individual.

Written instruction

The UKHSA PGD covers NHS commissioned services. It does not cover the provision of occupational health schemes or peer-to-peer influenza immunisation. Written instruction templates for the administration of inactivated influenza vaccine to staff in the course of an occupational health scheme will be published on the NHS Specialist Pharmacy Service website. The relevant written instruction template can be adopted by the organisations providing the immunisation service and authorised by an appropriate doctor, to provide an appropriate written instruction for the administration of seasonal flu vaccinations to employees.

Vaccine eligibility

Detailed descriptions of those eligible to receive the NHS-funded flu vaccine can be found in Chapter 19 of the Green Book and within the inclusion criteria for the appropriate vaccine Patient group direction (PGD) (live or inactivated).

Summary of eligible groups

The groups eligible for flu vaccination in the 2025 to 2026 flu season from 1 September 2025 include:

pregnant women
all children aged 2 or 3 years on 31 August 2025
all primary school aged children from reception to Year 6
secondary school-aged children in years 7 to 11 (individuals 18 years and over attending a special education needs (SEN) school and who are in a clinical risk group may also be vaccinated alongside their peers)
those aged 6 months to under 18 years in clinical risk groups (as defined in the Green Book, Chapter 19 (Influenza))

The groups eligible for flu vaccination in the 2025 to 2026 flu season from 1 October 2025 include:

those aged 65 years and over (including those who are 64 but will be 65 on or before 31 March 2026)
those aged 18 years to under 65 years in clinical risk groups (as defined in the Green Book, Chapter 19 (Influenza))
those in long-stay residential care homes and other long-stay care facilities where rapid spread is likely to follow introduction of infection and cause high morbidity and mortality (this does not include, for example, prisons, young offender institutions, university halls of residence)
carers in receipt of carer’s allowance, or those who are the main carer of an elderly or disabled person
close contacts of immunocompromised individuals
frontline workers in a social care setting without employer-led occupational health schemes including those working for

- a registered residential care or nursing home

- registered domiciliary care providers

- voluntary managed hospice providers

- those that are employed by those who receive direct payments (personal budgets) or Personal Health Budgets, such as personal assistants

All frontline healthcare workers, including both clinical and non-clinical staff who have contact with patients, should be offered influenza vaccine from 1 October 2025 as part of the organisations’ policy for the prevention of the transmission of influenza to help protect both staff and those that they care for.

Social care workers directly working with people clinically vulnerable to influenza should also have the influenza vaccine provided by their employer.

There are circumstances where frontline staff, employed by specific social care providers without access to employer-led occupational health schemes (see above), can access the vaccine through the NHS free of charge.

Patients not in a risk group for whom their clinician believes influenza vaccine would be beneficial

Clinicians should exercise professional judgement when assessing a patient and can recommend vaccination for individuals, even if they are not in a listed risk group, if influenza is likely to exacerbate their underlying medical condition.

Patients previously eligible for influenza vaccine but who are no longer in a risk group

Some patients may have been eligible to receive an NHS-funded influenza vaccine during previous flu seasons whilst in a clinical risk group but may no longer be in that group. Examples could include women who were pregnant during the last flu season but are not pregnant during this flu season or patients who were taking regular steroids during last flu season but are no longer taking them.

Provided that these patients are not in any other risk group described in the Green Book, they would not be eligible for flu vaccination this year. However, as above, clinicians can recommend vaccination for individuals, even if they are not in a listed risk group, if they believe that influenza is likely to exacerbate their underlying medical condition.

Timing of vaccination

The start of the adult programme for 2025 to 2026 will again be from the beginning of October (this year starting on the 1 October) with the majority of the vaccinations to be completed by the end of November. This later start date is based on the advice from JCVI concerning the waning of flu vaccine’s effectiveness in adults which means that it is preferable to vaccinate individuals closer to the time when the flu virus is likely to circulate (which typically peaks in December or January), as this will provide optimal protection during the highest risk period.

There are some exceptions to this later start date. Vaccination of pregnant women should continue to be offered from 1 September. One of the benefits of the flu vaccine is the protection it offers to the child in the first few months of life, when they are particularly vulnerable to flu. It is important to ensure that as many newborn babies as possible are protected during the flu season by not delaying vaccination for pregnant women. Therefore, no change in the timing of the offer for the maternal programme was advised by JCVI. Pregnant women are not expected to lose protection as rapidly as the elderly population – starting vaccination earlier (particularly in those women who are in the later stages of pregnancy) will still offer protection to women themselves in the peak season.

As flu circulation in children normally precedes that in adults, the children’s programme should continue to start from 1 September or as soon as delivery and supply of vaccine allows. Protection from the vaccine also lasts much longer in children, so the priority is to start vaccinating all children (including those in clinical risk groups) from September, both to provide early protection to children and to reduce transmission to the wider population. Starting the childhood flu vaccination programme in early September with rapid uptake could reduce rates of flu in older adults through indirect protection. As the public health benefit of vaccination is greater in younger children, where possible, school-aged immunisation providers are encouraged to schedule vaccination of primary school children early in the season. For school-aged cohorts, vaccination in schools should be completed by the second Friday in December (12 December 2025), with further catch-up opportunities provided via community clinics or additional school visits as appropriate.

Some special educational needs (SEN) schools cater for individuals up to 25 years of age. Any young person over 17 years of age in a clinical risk group and in a SEN school can be vaccinated alongside their peers, using LAIV or IIVc as appropriate. Due to clinical vulnerability, school-aged immunisation teams regularly prioritise SEN settings for vaccination in early September – at the beginning of the vaccination season which will be before the vaccination programme for individuals over the age of 18 years in clinical risk groups commences in October. Vaccination of all children and young people in SEN settings from 1 September is advised, even if a young person is over 17 years of age. LAIV off-label should be used in this cohort (if not otherwise clinically contraindicated). Young people are not expected to lose protection as rapidly as the elderly population and therefore offering vaccination early in the season, alongside their peers, will still offer protection to young people in peak season. As flu circulation in children normally precedes that in adults, vaccinating all children and young people in SEN settings over 17 years of age alongside their peers will protect them in the event of flu exposure in the setting early in the season and may also reduce anxiety by enabling them to be vaccinated in a familiar setting.

Following clinical assessment there may be a small number of other adults who would benefit from vaccination from 1 September. For example, for those who are due to commence immunosuppressive treatment (such as chemotherapy), having a flu vaccine before they start treatment would allow them to make a better response to their vaccination. GPs should use clinical judgement to bring forward vaccination in these exceptional circumstances.

Vaccination should be given in sufficient time to ensure patients are protected before flu starts circulating. If an eligible patient presents late for vaccination, it is generally appropriate to still offer it. This is particularly important if it is a late or prolonged flu season or when patients newly at-risk present, such as pregnant women who may not have been pregnant at the beginning of the vaccination period. The decision to vaccinate should take into account the fact that the immune response to vaccination takes about 2 weeks to fully develop.

Question 4

Pregnancy and breastfeeding

Accepted Answer

All pregnant women, including those who become pregnant during the flu season, should be offered an inactivated influenza vaccine, regardless of their stage of pregnancy. The vaccines recommended for use in pregnancy are cell-cultured inactivated influenza vaccine (IIVc) or recombinant inactivated influenza vaccine (IIVr). If these vaccines are not available, egg-cultured inactivated influenza vaccine (IIVe) can be used when every attempt to use IIVc or IIVr have been exhausted.

Influenza infection during pregnancy may be associated with perinatal mortality, prematurity, lower birth weight and smaller neonatal size in the infant (5, 6, 7), an increased risk of complications in the pregnant woman (8, 9) and admission to intensive care for both the infant and pregnant woman (10).

Studies have demonstrated that pregnant women can safely receive inactivated influenza vaccine during any trimester of pregnancy and that infants also receive some protection from maternal antibodies as a result of the woman having the vaccination whilst pregnant (11).

There is limited data on the use of live attenuated influenza vaccine in pregnancy. However, in a study of inadvertent LAIV administration to pregnant women, there was no evidence of significant maternal adverse outcomes (12). The live viruses in LAIV have been attenuated (weakened) and adapted to cold so that they can only replicate at the lower temperatures found in the nasal passage. These live viruses cannot replicate efficiently elsewhere in the body and therefore there is no theoretical basis for concern about infection of the unborn foetus or the pregnant woman’s lungs. Inactivated influenza vaccines are, however, preferred for those who are pregnant. There is no need to specifically ask about or test for pregnancy or ask about breastfeeding when offering LAIV to eligible girls or to advise avoidance of pregnancy or breastfeeding in those who have been recently vaccinated. The available evidence indicates that LAIV viruses are not excreted in breastmilk.

Adjuvanted egg-cultured inactivated influenza vaccine (aIIV) is licensed for use from 50 years of age but is not currently indicated for use in women who are, or may be, pregnant or breastfeeding. There is no data from the use of aIIV in pregnant women, although animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. This means that IIVc or IIVr are recommended for individuals who are pregnant or breastfeeding and aged 50 years or over.

Pregnant women can access the influenza vaccine from their GP, community pharmacy or through their maternity service provider.

Vaccination of women who become pregnant late in the flu season

Women who become pregnant during the flu season should be offered influenza vaccine as soon as possible. The timing of the flu season varies each year but usually commences later in December or in the New Year, followed by 2 to 3 months of flu transmission. Although it takes around 2 weeks to make a response to the flu vaccine, pregnant women and their unborn babies are at higher risk of influenza-associated morbidity and mortality and should still benefit from vaccination throughout the remaining season.

Administering influenza vaccine at the same time as whooping cough (pertussis) containing vaccine, respiratory syncytial virus (RSV) vaccine and/or anti-D immunoglobulin

Pregnant women should be offered the influenza vaccine as soon as the vaccine becomes available, regardless of their stage of pregnancy. Influenza vaccine should not be deferred in order to give it at the same appointment as the pertussis-containing vaccine or RSV vaccine for pregnant women.

Pertussis-containing vaccine is recommended for all pregnant women from 16 weeks of pregnancy but is generally offered at around 20 weeks. The RSV vaccine is offered from week 28 of pregnancy. If influenza vaccination season has commenced, then it is not recommended that pregnant women wait until they are eligible for other vaccines before having their influenza vaccine, as this would leave them, and their unborn baby, at risk of potentially severe illness if they develop flu.

The injected influenza, RSV and pertussis containing vaccines are inactivated vaccines and so can be administered at the same time, on the same day or with any interval between them, and they should be given at the recommended stage of pregnancy (from 16 weeks for pertussis containing vaccine, at week 28 or soon after for RSV vaccine and at any stage of pregnancy for influenza vaccine).

Anti-D immunoglobulin, where required, can also be given at the same time as, or at any interval before or after the influenza, RSV and pertussis-containing vaccines.

Administering influenza vaccine to breastfeeding women

Breastfeeding is not a clinical indication for influenza vaccination. However, inactivated influenza vaccine can be given to breastfeeding women if they are pregnant or in a clinical risk group.

Question 5

Influenza vaccine and its components

Accepted Answer

A table of all the influenza vaccines marketed in the UK for the 2025 to 2026 season has been published on the UKHSA annual flu page.

Vaccine antigens

Each year, the World Health Organization (WHO) monitors the epidemiology of influenza across the world and makes recommendations to vaccine manufacturers regarding the strains of influenza to include in the vaccine.

As egg-cultured and cell-cultured vaccine production systems differ, different viruses with similar properties are used to facilitate timely vaccine production. For cell-cultured vaccines, cell-isolated vaccine viruses would be recommended.

For the 2025 to 2025 flu season (northern hemisphere winter) WHO has recommended (13) that trivalent vaccines contain the following.

Egg-cultured vaccines:

an A/Victoria/4897/2022 (H1N1)pdm09-like virus
an A/Croatia/10136RV/2023 (H3N2)-like virus
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Cell-cultured or recombinant vaccines:

an A/Wisconsin/67/2022 (H1N1)pdm09-like virus
an A/District of Columbia/27/2023 (H3N2)-like virus
a B/Austria/1359417/2021 (B/Victoria lineage)-like virus

This vaccine composition differs from the 2024 to 2025 vaccine composition as one of the influenza A virus strains in each vaccine has been replaced, and one of the B strains has also been removed.

The continued absence of confirmed detection of naturally occurring B/Yamagata lineage viruses after March 2020 is indicative of a very low risk of infection by B/Yamagata lineage viruses and led to the WHO recommendation that inclusion of the B/Yamagata strain in influenza vaccines was no longer warranted (13). The recommendation to exclude this component as soon as possible and move from a quadrivalent to a trivalent formulation means that the B/Yamagata strain has been removed from all inactivated influenza vaccines used in the UK for the 2025 to 2026 flu season. It was removed from the LAIV in the previous flu season (2024 to 2025).

The Vaccine knowledge project inactivated flu vaccine webpage contains comprehensive information about the constituents of flu vaccines.

Egg allergy and ovalbumin content of influenza vaccines

There are 2 egg-free vaccines available for the 2025 to 2026 flu season. The cell-cultured inactivated influenza vaccine (IIVc) made by CSL Seqirus UK (licensed from 6 months of age) and the inactivated recombinant flu vaccine (IIVr) (licensed from 18 years of age).

The other inactivated influenza vaccines ( aIIV, IIV-HD and IIVe) contain traces of egg as the egg protein ovalbumin. The ovalbumin content of the flu vaccines for the 2025 to 2026 season is available in influenza vaccines marketed in the UK for the 2025 to 2026 season table on the Annual flu programme webpage.

JCVI has previously advised (14) that children aged 2 years and over with an egg allergy, including those with previous anaphylaxis to egg, can be safely vaccinated with LAIV in any setting (including primary care and schools). The only exception is for children who have required admission to intensive care for a previous severe anaphylaxis to egg, for whom no data is available, such children are best given LAIV in the hospital setting. LAIV remains the preferred vaccine for this group and the intranasal route is less likely to cause systemic reactions. The cell-cultured inactivated influenza vaccine (IIVc), which is egg-free, is a second-line alternative for this patient group.

Children with egg allergy (less severe than anaphylaxis requiring intensive care) but who also have another condition which contraindicates LAIV (for example, immunosuppression) should be offered either cell-cultured egg-free inactivated influenza vaccine (IIVc) or one with a very low ovalbumin content (less than 0.12 micrograms/ml). Inactivated vaccines with ovalbumin content more than 0.12 micrograms/ml (equivalent to 0.06 micrograms/ml for 0.5ml dose) or where content is not stated should not be used in egg-allergic children. If these children are aged under 9 years and have not previously been vaccinated against influenza, they will require a second dose of vaccine 4 weeks after the first.

Egg-allergic children with asthma can receive LAIV if their asthma is well controlled (see the advice on asthma in the precautions section, and see also above if the egg allergy has required intensive-care admission.

Adults with egg allergy can be immunised in any setting using an inactivated influenza vaccine with an ovalbumin content less than 0.12 micrograms/ml (equivalent to 0.06 micrograms per 0.5 ml dose), excepting those with severe anaphylaxis to egg that has previously required intensive care. These adults should be offered an egg-free vaccine (the cell-cultured inactivated influenza vaccine, IIVc or the egg-free recombinant vaccine, IIVr). If this is not possible, they should be referred to a specialist for assessment with regard to receiving immunisation in hospital.

Vaccine adjuvant in aIIV

Vaccine adjuvants can reduce the amount of virus required for the production of a vaccine, but they are primarily added to vaccines to enhance and lengthen the duration of the immune response. This is particularly important for those aged 65 years and older as the ageing immune system may result in a suboptimal response to influenza vaccine, and there is evidence of limited effectiveness of the unadjuvanted trivalent vaccines offered previously to those aged 65 years and over.

The aIIV vaccine contains an adjuvant called MF59C.1 which improves the immune system’s response to vaccination and helps it to produce more antibodies against the influenza virus strains in the vaccine. MF59C.1 is an oil-in-water emulsion of squalene oil, polysorbate 80, sorbitan trioleate, sodium citrate, citric acid and water for injections. Squalene is a naturally occurring substance that is found in humans, animals and plants. In humans, it is made in the liver and circulates in the bloodstream. Squalene is also found in a variety of foods, cosmetics, over-the-counter medications and health supplements. The squalene used in pharmaceutical products and vaccines is commercially extracted from fish oil and is then highly purified during the manufacturing process.

A single dose of aIIV contains less than 10mg of squalene. To put this in context, over 1,000mg of squalene is made in the liver every day, and humans ingest around 50mg to 200mg of squalene every day in a normal diet (15).

Polysorbate 80, sorbitan trioleate and sodium citrate are emulsifiers that stop the squalene oil from separating out of the water in the vaccine. These, along with citric acid (also contained in the adjuvant) are all commonly used in foods and drinks.

Latex

The influenza vaccines for 2025 to 2026 are not contraindicated in latex allergic individuals. The vaccine components (such as the plunger stopper) that are in contact with the injection solution or suspension are latex-free.

As with all vaccines, immunisers must be trained in the management of anaphylaxis, and an anaphylaxis pack must always be available whenever vaccines are given.

Antibiotics

Some egg-cultured inactivated influenza vaccines may contain residues of antibiotics that are used during the vaccine manufacturing process, such as kanamycin and neomycin sulphate. Patients with a severe or anaphylactic allergy to any vaccine components, including antibiotic residues, should be offered an alternative vaccine.

The CSL Seqirus UK cell-cultured inactivated influenza vaccine (IIVc) and Sanofi’s recombinant vaccine (IIVr, Supemtek) do not contain any antibiotics as these are not made in eggs which means that there is no need to use antibiotics during the manufacturing process.

Question 6

Recommendations for the use of inactivated influenza vaccine

Accepted Answer

For the 2025 to 2026 flu season, JCVI has advised the following vaccines be used (16). A visual aide of the vaccines for the 2025 to 2026 season and the groups that they should be given to is also available. A poster of this guidance can be downloaded or ordered from Health Publications.

Table 1. Recommendations for the use of inactivated influenza vaccines

Eligible group	Type of influenza vaccine
Those aged 65 and over and those who will become 65 before 31 March 2026	aIIV or IIV-HD or IIVr use IIVc only when every attempt to use aIIV or IIV-HD or IIVr has been exhausted
Those aged 18 to less than 65 in eligible clinical risk groups	IIVc, IIVr or aIIV (in those from 50 years of age); IIV-HD (in those from 60 years of age) – the egg-cultured inactivated influenza vaccine (IIVe) can also be considered only when every attempt to use IIVc, IIVr, aIIV (in those from 50 years of age) or IIV-HD (in those from 60 years of age) has been exhausted
Children aged 2 years and over if LAIV is contraindicated or otherwise unsuitable (for example parents object to LAIV on the grounds of its porcine gelatine content or child has contact with a very severely immunocompromised individual)	IIVc IIVe can also be considered only when every attempt to use IIVc has been exhausted
Infants aged 6 months to 2 years in a clinical risk group	IIVc IIVe can also be considered only when every attempt to use IIVc has been exhausted

Ahead of the flu season first line vaccines should always be ordered for a given cohort. Once the vaccination campaign has started, if providers need additional stock, second line vaccines should only be ordered if first line options are not available to order. Clinics should be planned using the recommended first line vaccine. Where a provider does not have a first line vaccine in stock, patients should be directed to an alternative provider who has stock of a first line vaccine or told to rebook when the new stock is available. Vaccination with a second line vaccine should only be considered on an exceptional basis where there is a valid reason why the patient may not return for a further appointment. Practices and community pharmacy should aim to minimise the need for this by procuring adequate stock before the campaign starts.

Adults 65 years of age and over and those who will become 65 before 31 March 2026

For vaccination of those aged 65 years and over in the 2025 to 2026 flu season, and those aged 64 years who will become 65 years old before 31 March 2026, JCVI advises the use of the following inactivated vaccines:

adjuvanted inactivated influenza vaccine (aIIV)
high-dose inactivated influenza vaccine (IIV-HD)
recombinant inactivated influenza vaccine (IIVr)

Cell-cultured inactivated influenza vaccine (IIVc) should only be offered to this age cohort in circumstances where the preferred first line influenza vaccines are not available.

Adults in clinical risk groups aged under 65 years and pregnant women

Adults in clinical risk groups, including pregnant women, aged 18 to less than 65 years old should be offered:

cell-cultured inactivated influenza vaccine (IIVc)
recombinant inactivated influenza vaccine (IIVr)

Adults in clinical risk groups aged 50 years and over can also be offered the adjuvanted inactivated influenza vaccine (aIIV) in line with the product licence.

Adults in clinical risk groups aged 60 years and over can also be offered the high-dose inactivated influenza vaccine (IIV-HD) in line with the product license.

The egg-cultured inactivated influenza vaccine (IIVe) can also be considered only where the preferred first line influenza vaccines are not available to order.

Limited evidence shows there is a potential advantage to using cell-cultured inactivated influenza vaccines compared with egg-cultured inactivated influenza vaccines, due to the possible impact of ‘egg-adaption’ on vaccine effectiveness, particularly against A(H3N2) strains (see section about IIVc for explanation of egg-adaptation’). The evidence on additional benefit is available for only a few seasons but the issue of egg adaptation remains a real concern, particularly for the A(H3N2) virus which is the more virulent influenza subtype in terms of morbidity and mortality.

JCVI support a clear preference for IIVc or IIVr, (as well as aIIV for those aged from 50 years and IIV-HD for those aged from 60 years) over IIVe for adults in this group. However, the egg-cultured inactivated influenza vaccine (IIVe) can be given to this age group where the preferred first line influenza vaccines are not available because any impact of egg adaptation is thought likely to be limited to seasons in which the influenza season is dominated by well-matched H3N2 strains.

aIIV, IIV-HD or IIVr are the first line vaccines recommended for people aged 65 years and over (or turning 65 years by 31 March). If not available through Occupational Health (OH), the OH provider should advise that the staff member can have these from a GP or pharmacy if they wish. If IIVc is available in OH, this is the acceptable second-line vaccine for this age group and can be offered if the staff member does not wish to attend their GP surgery or pharmacy.

If the OH provider only has IIVe available, they should recommend that health and social care workers aged 65 years and over go to their GP surgery or pharmacy for vaccination with one of the JCVI-recommended vaccines for their age group.

Individuals working with animals at risk of zoonotic influenza

Seasonal influenza vaccination should be considered for those at higher risk of infection with zoonotic influenza related to their work or similar exposures (JCVI June 2023, JCVI June 2024).

It is possible that co-infection of zoonotic influenza viruses with seasonal human influenza viruses will occur in people in close contact with infected animals (e.g. poultry, wild birds, cattle, pigs). Co-infecting viruses have the potential to undergo reassortment, with a theoretical risk of resulting in a human-transmissible virus. Vaccination may reduce the risk of infection with seasonal influenza viruses and therefore reduce the very small theoretical risk of reassortment events.

People at highest risk are likely to be those undertaking culling or cleaning at confirmed zoonotic influenza outbreak premises or handling live unwell animals. Workers employed at, or regularly visiting, statutorily-registered poultry, swine or cattle units and poultry, swine or cattle processing units may also be at risk if they have direct exposure to bird, swine or cattle faeces or litter such as through initial egg sorting or cleaning of premises. People involved in collection of wild bird carcasses where avian influenza is suspected should also be considered for vaccination.

Where indicated an inactivated influenza vaccine should be offered in line with age-related recommendations.

Children in clinical risk groups for whom live flu vaccine (LAIV) is contraindicated

LAIV is not licensed for use in those aged 6 months to less than 2 years, eligible children in this age group in a clinical risk group are recommended to receive the cell-cultured inactivated influenza vaccine (IIVc). IIVc will be centrally supplied for these children and should be ordered through ImmForm. IIVe can also be considered for use in this age group if IIVc is not available, but this is not available from ImmForm (UKHSA has not procured IIVe for this purpose).

If LAIV is contraindicated or otherwise unsuitable for children aged from 2 years old to less than 18 years, they should be offered IIVc. IIVe can also be considered for use in this age group if IIVc is not available. IIVc will be centrally supplied for these children and should be ordered through ImmForm. UKHSA has not procured IIVe for this purpose.

Children who are close/household contacts of very severely immunosuppressed people (for example bone marrow transplant patients requiring isolation) should also be offered inactivated rather than live influenza vaccine.

Children whose parents decline LAIV

If the parent of an eligible child refuses LAIV because of its porcine gelatine content (and they understand that it is the preferred vaccine for children as it is quick, easy and painless to deliver and may also be better at reducing the spread of flu in the community), they should be offered an alternative injectable vaccine. IIVc will also be centrally supplied for these children and should be ordered through ImmForm.

Question 7

Inactivated vaccines available during 2025 to 2026

Accepted Answer

Some inactivated influenza vaccines are restricted to use in particular age groups or are not suitable for those with an egg allergy. Those administering influenza vaccines must be familiar with and refer to the manufacturer’s SmPC for individual brands when administering inactivated influenza vaccines.

Changes to the inactivated influenza vaccines for the 2025 to 2026 flu vaccination season

All the inactivated vaccines recommended for use in 2025 to 2026 flu vaccination season are trivalent influenza vaccines and contain 2 influenza A strains and 1 influenza B strain.

This is a change from recent previous seasons where quadrivalent formulations (containing 2 influenza A strains and the two main influenza B strains) were used.

Historically some inactivated influenza vaccines had been trivalent (the adjuvanted inactivated influenza vaccine (aIIV) was trivalent until 2021 to 2022 season) although the influenza strains that they previously protected against were different to the current compositions.

The move from quadrivalent to trivalent for the inactivated vaccines for the 2025 to 2026 season followed the recommendation from the WHO influenza vaccine composition advisory committee in 2023 that the B/Yamagata lineage antigen should be excluded from future influenza vaccines. They advised that it is no longer necessary as there have been no confirmed naturally occurring B/Yamagata lineage virus detections after March 2020.

The trivalent vaccine offers the same level of protection against the 2 A and 1 B flu virus strains as the quadrivalent vaccines did.

The live attenuated influenza vaccine (LAIV), administered nasally and licensed for use in children from 2 years of age, had already moved to a trivalent formulation in time for the 2024 to 2025 flu vaccination campaign. This means that all the influenza vaccines used in the UK for the 2025 to 2026 season will be trivalent formulations.

Inactivated influenza vaccines

Inactivated influenza vaccines may be either egg-cultured, cell-cultured or recombinant.

Adjuvanted inactivated influenza vaccines (aIIV)

Adjuvanted vaccines are vaccines that have a substance added to them to enhance the immune response made. More information can be found in the section on influenza vaccine components.

Published data indicated that an adjuvanted inactivated influenza vaccine had higher immunogenicity and effectiveness than non-adjuvanted vaccines in older people and in 2017, it was licensed for use in those aged 65 years and older in the UK. This vaccine was initially licensed as a trivalent formulation, then became a quadrivalent vaccine and for the 2025 to 2026 flu season, will become a trivalent formulation once again. Whilst it was previously licensed from 65 years of age, it is now licensed from 50 years of age.

The adjuvanted influenza vaccine has been widely used in the UK for the past 7 flu seasons.

Cell-cultured inactivated influenza vaccine (IIVc)

The cell-cultured inactivated influenza vaccine (IIVc) was first used in the UK in the 2019 to 2020 flu season and contains whole inactivated virus. Previously, virtually all influenza vaccines had been cultured in fertilised chicken eggs but when flu vaccine viruses are grown this way, the viruses adapt to live in the egg. This can lead to changes in the viruses during the manufacturing process which means the egg-derived virus used in the vaccine is then not a complete antigenic match to the original wild-type strain recommended by the WHO. This means the vaccine virus may not match the circulating flu strain as closely and the vaccines produced may therefore not be as effective. Although this ‘egg adaptation’ has been known about for a long time, it has become more of a problem in the last decade, particularly for the A(H3N2) virus which appears to be more affected by egg adaptation than the other flu A and B viruses.

The cell-cultured vaccine manufacturing process used to make the cell-cultured flu vaccine (IIVc) manufactured by Seqirus, uses the Madin-Darby Canine Kidney (MDCK) cell line to grow the influenza virus. The original cells in this cell line were taken by Madin and Darby from the kidney tubule of an adult dog in 1958. This is the cell line that is still used today so the cell-cultured manufacturing process does not require any new cells to be taken (17). The MDCK cell line is used because the influenza virus grows well in it, it is able to produce high volumes of flu virus for use in vaccines and the influenza virus isolated following culture in these cells retains the antigenic properties of the original strain. This method of vaccine virus production should result in the vaccine virus being a closer match to the wild-type circulating flu viruses. After the vaccine viruses are grown, they are highly purified in a purification process that removes the cell culture materials. This means that it is unlikely that any cell culture material remains in the vaccine.

Non-egg cultured vaccines, such as the cell-cultured inactivated influenza vaccine (IIVc), are also widely used in the USA and in multiple European countries. The cell-cultured inactivated influenza vaccine (previously known by the brand name: Flucelvax) was first approved for use in the USA in 2013. Since eggs are not required to grow the flu virus, the cell-cultured flu vaccines (IIVc) contain no egg and they also do not contain any live virus, antibiotics or gelatine.

Further information on how cell-cultured flu vaccines are made is available from the Centers for Disease Control and Prevention.

High dose inactivated influenza vaccine (IIV-HD)

The split virion high dose inactivated influenza vaccine (IIV-HD) contains four times the amount of antigen that standard dose flu vaccines contain (60 micrograms of haemagglutinin of each of the virus strains per dose compared to 15 micrograms of each in the inactivated influenza standard dose vaccines).The higher dose of antigen in the vaccine is intended to enhance the immune response made by people aged from 60 years and therefore, provide them with better protection against flu. Studies have shown that IIV-HD is more effective in older adults than the standard dose influenza vaccine and that they made higher antibody levels following receipt of IIV-HD than they made to a standard dose of influenza vaccine.

The flu viruses in the IIV-HD vaccine are grown in eggs – see explanation in ‘Egg-cultured inactivated influenza vaccine (IIVe)’ section below as to how these vaccines are made. Because they contain traces of egg (as ovalbumin, equal to or less than 1 microgram per 0.5ml dose), IIV-HD should not be given to those with an egg allergy (see section on ‘egg allergy and ovalbumin content’ for those with egg allergy).

The type of local and systemic reactions most commonly reported following vaccination with IIV-HD (pain at injection site, muscle ache, headache and malaise) are reported to be mild to moderate, similar to those seen following vaccination with other influenza vaccines and resolve within a few days. However, some side effects are reported slightly more frequently after vaccination with IIV-HD than after standard dose inactivated influenza vaccines. Overall, adverse reactions are generally less frequent in participants aged 65 years and older than in participants aged 60 to 64 years.

The IIV-HD vaccine is made by Sanofi and was licensed for use in the UK by the MHRA in 2019. It is widely used in the USA.

Recombinant inactivated influenza vaccine (IIVr)

Supemtek (IIVr) is an inactivated influenza vaccine made using recombinant DNA technology. It does not require the use of, or growth of influenza virus during the manufacturing process which means that the antigen in the vaccine cannot adapt or mutate and should therefore be an exact match to the flu A and B strains in the WHO recommendations for the vaccine. It also contains 3 times the amount of flu virus haemagglutinin antigen contained in standard inactivated influenza vaccines in order to enhance the immune response made to it.

To make recombinant influenza vaccine, the manufacturer takes the DNA (genetic instructions) for making the surface protein, haemagglutinin, found on flu viruses. The haemagglutinin DNA is then combined with a baculovirus (a virus that infects invertebrates). This results in a ‘recombinant’ virus. The role of the baculovirus is to help transport the DNA instructions for making the haemagglutinin antigen into a host cell. Once the recombinant virus enters the host cell line (an insect cell line in which the baculovirus grows well), it instructs the cells to rapidly produce the haemagglutinin antigen. This antigen is grown in bulk, collected, purified, and then packaged as recombinant flu vaccine. When the vaccine is injected, the haemagglutinin antigen in it triggers the immune system to create antibodies that specifically target the flu virus.

The type and rates of local and systemic reactions following vaccination with IIVr are similar to those seen following vaccination with other flu vaccines (injection site tenderness, headache, fatigue, muscle ache and joint pain).

Non-egg-cultured vaccines (such as the cell-cultured inactivated influenza vaccine (IIVc) and recombinant inactivated influenza vaccine (IIVr)) are also widely used in the USA and in multiple European countries. The recombinant influenza vaccine was first approved for use in the USA in 2016 where it is known as Flublok. In the UK, IIVr is licensed as Supemtek. Since eggs are not required to grow the flu virus, cell-cultured influenza vaccines (IIVc and IIVr) contain no egg, and they also do not contain any live virus, antibiotics or gelatine.

Further information on how cell-cultured and recombinant flu vaccines are made is available from the Centers for Disease Control and Prevention.

Egg-cultured inactivated influenza vaccine (IIVe)

Egg-cultured influenza vaccines are propagated in fertilised hens’ eggs from healthy chicken flocks using a process that has been used for more than 70 years. Vaccine viruses are injected into the eggs and incubated to allow the virus to grow. After several days, the fluid is drawn from the eggs and the viruses in the fluid are killed and purified and form the basis of the egg-cultured inactivated influenza vaccines.

The egg-cultured inactivated influenza vaccine (IIVe) for use in the 2025 to 2026 season protects against 3 strains of flu: influenza A subtypes H1N1(pdm09) and H3N2, and the B/Victoria lineage. This vaccine can be considered for use in pregnant women and adults in clinical risk groups aged less than 65 years if the recommended vaccines are not available as any impact of egg adaptation is likely to be limited to influenza seasons dominated by well-matched H3N2 strains. However, JCVI supports a preference for IIVc, IIVr, aIIV (for those aged 50 years) and IIV-HD (for those aged 60 years and over) in line with their licenses over IIVe for these groups. IIVe can also be offered to children in clinical risk groups aged 6 months to 18 years if LAIV is contraindicated or not suitable and IIVc is not available.

Question 8

Live attenuated influenza vaccine (LAIV)

Accepted Answer

Presentation of LAIV

LAIV is supplied in a box containing 10 single-use, prefilled nasal applicators. Each applicator contains 0.2ml nasal suspension. The nasal applicator is ready to use and the vaccine does not require reconstitution or dilution. The nasal suspension is colourless to pale yellow, clear to opalescent though small white particles may be present.

LAIV applicator components

The LAIV is supplied in a single use nasal applicator (type 1 glass) with nozzle (polypropylene with polyethylene transfer valve), nozzle tip-protector (synthetic rubber), plunger rod, plunger stopper (butyl rubber) and dose divider clip, none of which should affect individuals with latex sensitivity.

LAIV efficacy

LAIV provides good overall protection for children against influenza virus and is expected to provide some cross-protection against mismatched strains. Using a live attenuated vaccine provides more antigenic stimuli. More elements of the immune system are involved, resulting in the production of IgA antibody (important in mucosal immunity) and cell mediated immunity including T-cell responses. Vaccine effectiveness varies from season to season depending upon the circulating strains and the vaccine composition. The estimated vaccine effectiveness against primary care influenza attendances in 2- to 17-year-olds for 2024 to 2025 was 56% (the majority of children will have received LAIV).

Cold adapted influenza virus

The live viruses in LAIV are cold adapted so that they cannot replicate efficiently at body temperature (37°C). This means that the vaccine viruses will not replicate in the lungs but will reproduce at the cooler temperatures found in the nose (nasal mucosa). This allows the child to produce localised antibodies in the lining of the airways which then protect against infection if they encounter flu virus (which enters the body via the nose and mouth).

These localised antibodies are not produced in response to the inactivated influenza vaccine. In addition to localised antibodies in the nose, antibodies are also produced in the blood (systemic antibodies).

Cold adaption, in addition to the attenuation (virus weakening) process, means that LAIV cannot cause clinical flu in immunocompetent children.

Transmission of vaccine virus in LAIV

There is a theoretical potential risk of transmission of the live attenuated flu virus in LAIV to very severely immunosuppressed contacts (for example bone marrow transplant patients requiring isolation) for 1 to 2 weeks following vaccination. Following extensive use of LAIV in the UK (over 34 million doses), there have been no reported instances of illness or infections from the vaccine virus among immunosuppressed patients inadvertently exposed. Where close contact with very severely immunosuppressed contacts (for example close/household members) is likely or unavoidable however, consideration should be given to using an appropriate inactivated influenza vaccine instead.

Healthcare workers and school staff may be asked questions in relation to the safety of the LAIV being given in schools. Specific information on potential exposure during administration, and from recently vaccinated children, is outlined below.

The nasal influenza vaccine uses a live attenuated (weakened) influenza virus which helps protect against influenza infection in those who receive it. LAIV does not cause clinical influenza in those immunised and is offered to children because it provides good overall protection for children against influenza virus and is expected to provide some cross-protection against mismatched strains. It has a good safety record and is easier to administer than injected vaccines. Millions of doses of LAIV have been given in north America and worldwide. In the UK, over 34 million doses have been given to young children and to school age children since 2013. A small number of respiratory illnesses (including wheeze) were reported in the contacts of vaccinated children. Most of these events were self-limiting and some of them are likely to have been coincidental.

LAIV has a good safety record and unvaccinated contacts are not at risk of becoming seriously ill with the influenza vaccine virus, either through being in the same room where influenza vaccine has been given or by being in contact with a recently vaccinated individual. Excluding children from school during the period when LAIV is being offered or in the following weeks is therefore not considered necessary. The only exception to this would be the tiny number of children who are extremely immunosuppressed (for example, those who have just had a bone marrow transplant). These children are normally advised not to attend school anyway because of the definite and much higher risk of being in contact with other infections, including ‘wild’ influenza, that spread in schools.

Exposure to vaccine virus during administration

Administration of the vaccine is via a nasal applicator which delivers 0.1ml (around one-fiftieth of a teaspoon) of fluid into each nostril. There is not a ‘mist’ of vaccine virus in the air when children are being vaccinated and therefore others in the room should not be at risk of ‘catching’ the vaccine virus. The room or school in which administration of nasal influenza vaccine has taken place does not require any special cleaning afterwards.

Images of the vaccine being squirted into the air (which are widely available on the internet) and the USA name of the vaccine (FluMist) may give a false impression that a vaccine mist fills the room. These images are intended to show how gently the vaccine comes out when inserted into the nose, but the vaccine does not create an external mist – almost all the fluid is immediately absorbed into the child’s nose where it has been sprayed.

Healthcare workers administering LAIV may, theoretically, be exposed to the vaccine virus if it is accidentally released outside of the child’s nose. In the USA, where there has been extensive use of the vaccine over many years, transmission of the vaccine virus to healthcare workers has not been reported to date. Healthcare workers who are immunosuppressed and those who are pregnant can safely administer the vaccine. As a precautionary measure, however, very severely immunosuppressed healthcare workers should not administer LAIV.

Shedding of vaccine virus

Although vaccinated children are known to shed virus for a few days after vaccination, it is less able to spread from person-to-person than the natural infection. The amount of virus shed is normally below the levels needed to pass on infection to others and the virus does not survive for long outside of the body. This is in contrast to natural flu infection, which spreads easily during the flu season. In schools where LAIV is administered therefore, the overall risk of contact with influenza viruses is massively reduced by having a large number of children vaccinated, thus reducing their risk of wild flu infection.

In the USA, where there has been extensive use of LAIV for many years and the UK, where over 34 million doses of the LAIV have been given, serious illness amongst immunocompromised contacts who are inadvertently exposed to vaccine virus has never been observed. Expert doctors at Great Ormond Street Hospital, who deal with many children with very serious immune problems, do not recommend keeping such children off school purely because of LAIV vaccination.

Question 9

Number of influenza vaccine doses required (inactivated and LAIV vaccines)

Accepted Answer

Healthcare professionals are reminded that in some circumstances, the recommendations regarding vaccines given in the Green Book chapters may differ from those in the SmPC for a particular vaccine. When this occurs, the recommendations in the Green Book are based on current expert advice received from the JCVI and this advice should be followed. The Green Book recommendations and/or further advice from the Department of Health and Social Care and UKHSA is reflected in PGDs.

Children who have received one or more doses of any influenza vaccine before should be considered as previously vaccinated. Children who are under 9 years of age and are in a clinical risk group should receive 2 doses if it is the first year that they are receiving any flu vaccine. In subsequent years, they can be given a single dose as their immune system will already have been primed.

The marketing authorisation holder’s Summary of Product Characteristics (SmPC) for Fluenz states that, for children who have not previously been vaccinated against seasonal flu, a second dose should be given after an interval of at least 4 weeks. The JCVI has considered this issue and has recommended that as a second dose of the vaccine provides only modest additional protection, children who are not in a clinical risk group should be offered a single dose of LAIV.

Children under 9 years of age who are close or household contacts of immunocompromised persons should have 2 doses in their first year of influenza vaccination, in line with the recommendations for children in clinical risk groups (unless LAIV is contraindicated, for example if contact is severely immunocompromised).

Age 0 to 6 months

Influenza vaccine is not licenced for use in infants less than 6 months old although they may develop some protection through the transfer of maternal antibodies if the pregnant woman is vaccinated during pregnancy.

Age 6 months to 2 years and not in a clinical risk group

Infants and children aged 6 months to 2 years who are not in a clinical risk group are not eligible to receive influenza vaccine as part of an NHS funded vaccination programme.

Age 6 months to 2 years and is in a clinical risk group or is a household contact of an immunocompromised person

Influenza vaccine is recommended for infants and children aged 6 months to 2 years who are in a clinical risk group or are close or household contacts of immunocompromised persons. LAIV is not licenced or recommended for use in this age group.

Children aged 6 months to 2 years in either of these two categories who have never received influenza vaccine in previous flu seasons should receive 2 doses (0.5ml) of the cell cultured inactivated influenza vaccine (IIVc) with a 4 week interval between doses.

Those children who have received one or more doses of influenza vaccine in previous flu seasons should be considered as previously vaccinated and only require a single dose (0.5ml) of influenza vaccine each season.

IIVe can also be considered for use in this age group if IIVc is not available.

Age 2 years to less than 9 years in a clinical risk group or is a household contact of an immunosuppressed individual

Children aged 2 to 9 years who are in a clinical risk group or are close or household contacts of an immunosuppressed individual and have never previously received any influenza vaccine should be offered 2 doses of LAIV with a minimum of a 4 week interval between them. Those children who have received a dose of influenza vaccine in a previous flu season only require a single dose in subsequent years.

If LAIV is contraindicated or is otherwise unsuitable for these children, 2 doses of a suitable age appropriate inactivated vaccine should be given with a 4 week interval between doses. The inactivated flu vaccines are interchangeable so the second dose does not have to be the same vaccine as given for the first dose.

If the child is a close or household contact of a very severely immunosuppressed individual (for example, bone marrow transplant patients requiring isolation) an inactivated influenza vaccine should be given instead of LAIV.

Age 2 years to less than 9 years and not in a clinical risk group

Children not in clinical risk groups (and who are not household contacts of immunocompromised persons) only require one dose of LAIV. A single LAIV dose is 0.2ml (administered as 0.1ml per nostril).

Healthy children aged 2 to 9 years who cannot receive LAIV due to contraindications or whose parents request they receive inactivated influenza vaccine instead of LAIV should be offered a single dose of inactivated vaccine (preferably IIVc), even if they have not previously received flu vaccine.

Age 9 years to less than 18 years

All eligible children aged 9 years to less than 18 years should be offered a single dose of LAIV (unless contraindicated). A single LAIV dose is 0.2ml (administered as 0.1ml per nostril). Children of this age who are in clinical risk groups or who are household contact of immunocompromised persons should receive a single dose even if it is the first season they are vaccinated against influenza. They are likely to have been primed by previous exposure to flu in previous seasons.

18 years and over (including pregnant women of any age)

A single 0.5ml dose of an inactivated influenza vaccine is recommended for eligible adults aged 18 years of age or older each year that they are eligible. This includes pregnant women of any age, health and social care workers and those aged 65 years and over.

Question 10

Contraindications and precautions

Accepted Answer

There are very few individuals who cannot receive any influenza vaccine. When there is doubt, appropriate advice should be sought promptly from the local NHS England Screening and Immunisation team, local UKHSA health protection team or an appropriate secondary care consultant to minimise the period the individual is left unvaccinated.

Inactivated influenza vaccine and LAIV

Inactivated influenza vaccine and LAIV are contraindicated for all patients who have had:

a confirmed anaphylactic reaction to a previous dose of influenza vaccine
a confirmed anaphylactic reaction any of the vaccine components (see section on egg content above for those with egg allergy)

Additional contraindications for LAIV

LAIV should not be given to a child or adolescent who is:

under 24 months or 18 years or older ^{[footnote 2]}
clinically severely immunodeficient due to conditions or immunosuppressive therapy, including acute and chronic leukaemias; lymphoma; cellular immune deficiencies; HIV infection not suppressed by antiretroviral therapy (HAART)
taking high dose corticosteroids
receiving salicylate therapy (see below)
pregnant

LAIV is not contraindicated for use in children or adolescents living with HIV who are receiving antiretroviral therapy and attaining viral suppression or for those receiving topical steroids, standard dose inhaled corticosteroids, low-dose systemic corticosteroids or those receiving corticosteroids as replacement therapy, for example for adrenal insufficiency.

The SmPC for LAIV lists salicylate use among children and adolescents as a contraindication for LAIV because of reports of the association of Reye’s syndrome with salicylates and wild-type influenza infection. No direct association between salicylate therapy and LAIV and Reye’s syndrome has been described and it is included on the SmPC on theoretical grounds only. As a precaution children and adolescents receiving salicylate therapy that has been associated with Reye’s syndrome (such as systemic aspirin therapy) should not be offered LAIV, however, LAIV can be offered to children and adolescents receiving salicylates that are not associated with Reye’s syndrome such as salicylates given for topical treatment of localised conditions or aminosalicylates for inflammatory bowel disease.

The Green Book chapter on ‘contraindications and special considerations’ (chapter 6) gives further advice on the use of live vaccines in individuals who are severely immunosuppressed. Where LAIV is contraindicated, inactivated flu vaccine should be offered instead.

Risk of anaphylaxis following administration of inactivated influenza vaccine or LAIV

As with all vaccines, there is a very rare possibility of any influenza vaccine causing a severe allergic reaction (anaphylaxis). All healthcare professionals who administer vaccines should be trained to recognise and treat anaphylaxis.

For a full list of influenza vaccine components, please see the manufacturer’s SmPC available on the Electronic Medicines Compendium website. The SmPC for individual products should be referred to when assessing the suitability of the vaccine for the patient (for example if they have an egg or antibiotic allergy).

Acute exacerbation of asthma symptoms

LAIV is not recommended for children and adolescents currently experiencing an acute exacerbation of asthma symptoms including those who have had increased wheezing and/or needed additional bronchodilator treatment in the previous 72 hours. Such children should be offered a suitable inactivated influenza vaccine to avoid a delay in protection.

There are limited safety data in children who require regular oral steroids for maintenance of asthma control or have previously required intensive care for asthma exacerbation – such children should only be given LAIV on the advice of their specialist. As these children may be at higher risk from influenza infection, those who cannot receive LAIV should receive a suitable inactivated influenza vaccine, (preferably IIVc).

Temporary deferral of immunisation

If an individual is acutely unwell or there is evidence of current neurological deterioration, temporary deferral of vaccination may be considered to avoid incorrect attribution of any change in the underlying condition. This is to avoid confusing the differential diagnosis of any acute illness by wrongly attributing any signs or symptoms to any adverse effects of the vaccine. However, minor illnesses without fever or systemic upset are not valid reasons to postpone immunisation.

The risk of deferring the vaccine should be balanced against the risk of flu and vaccination should be promptly given once the diagnosis and/or the expected course of the condition becomes clear.

This precaution does not apply to individuals with a chronic neurological condition that places them at risk of complications of influenza who should be offered vaccine once influenza vaccine stock becomes available.

Question 11

Vaccine ordering and national supply of additional adult vaccine

Accepted Answer

A list of vaccines available for the 2025 to 2026 flu programme is available on the annual flu pages of the GOV.UK website.

General practices and community pharmacies are responsible for ordering inactivated influenza vaccine for eligible patients aged 18 years and over directly from the manufacturer.

As some influenza vaccines may be restricted for use in particular age groups, the SmPCs for individual products should always be referred to when ordering vaccines to ensure that they can be given appropriately to particular patients or patient age groups.

UKHSA procures and supplies the vaccines for the children’s programme. LAIV and the inactivated injectable influenza vaccine IIVc for children can be ordered through the ImmForm website.

LAIV for all children aged from 2 years old and in eligible school years and children in clinical risk groups aged from 2 years to less than 18 years, except when contraindicated or otherwise unsuitable.
IIVc for children aged 2 years to less than 18 years in clinical risk groups for whom LAIV is medically contraindicated or otherwise unsuitable (for example, parents decline LAIV because of the porcine gelatine content).
IIVc for children aged 6 months to 2 years in clinical risk groups.

Ordering controls and excess stock

It is important not to order or hold more than 2 weeks’ worth of LAIV as local stockpiling can cause delays in stock being released and increases the risk of significant loss if there are cold chain failures. It also increases the risk of out of date vaccine being used as LAIV has a short shelf life.

In previous flu seasons, ordering controls using allocations based on previous years uptake were introduced on centrally supplied flu vaccines. These were put in place to reduce the amount of excess vaccine, in particular LAIV, ordered by providers but not administered to children. Ordering controls will also be in place in 2025 to 2026. Further information on ordering controls and other ordering advice for LAIV will be available in Vaccine Update and on the ImmForm news item both prior to, and during, the influenza vaccination period.

Question 12

Vaccine storage

Accepted Answer

Storage of inactivated influenza vaccine

Inactivated influenza vaccines must be stored in accordance with the manufacturer’s instructions between +2°C and +8°C, in their original packaging and protected from light. These vaccines must not be frozen and should not be exposed to heat as this can lead to a decline in potency and subsequent reduced shelf life.

Storing LAIV

LAIV must be stored in accordance with the manufacturer’s instructions between +2°C and +8°C, in its original packaging and protected from light. This vaccine must not be frozen and should not be exposed to heat as this can lead to a decline in potency and subsequent reduced shelf life.

The SmPC for LAIV states “stability data indicate that the vaccine components are stable for 12 hours when stored at temperatures from 8°C to 25°C. At the end of this period, Fluenz should be used immediately or discarded”. If LAIV is involved in a cold chain failure incident, do not immediately dispose of the vaccine. Label and isolate the vaccine involved, keep it between +2 to +8°C, and seek further advice from the local Screening and Immunisation team and the vaccine manufacturer.

Shelf life of LAIV

LAIV has an expiry date 15 weeks after manufacture. This is much shorter than inactivated injectable influenza vaccines. Expiry dates should be checked regularly, and all efforts should be made to use the vaccine as soon as possible.

Expired doses of any influenza vaccine

Inactivated influenza vaccines or LAIV from previous years’ programmes should be discarded before stock for the current year is received.

Vaccine storage incidents

Should vaccines be inadvertently stored outside the recommended temperature range of +2°C to +8°C, the vaccine should be quarantined, and risk assessed for suitability of continued off-label use or appropriate disposal. Refer to the Vaccine Incident Guidance document and seek further advice on vaccine stability and cold chain storage incidents from the vaccine manufacturer and your local Screening and Immunisation team.

Question 13

Influenza vaccine preparation

Accepted Answer

Preparation of inactivated influenza vaccines

Inactivated flu vaccines are presented as prefilled syringes for intramuscular injection. Vaccines in prefilled syringes may contain an air bubble. This should not be expelled unless it is specifically stated to do so in the vaccine SmPC. To try to expel it risks accidentally expelling some of the vaccine and therefore not giving the patient the full dose. Once injected, the air bubble forms an airlock preventing the vaccine seeping out along the needle track into subcutaneous tissue and onto the skin. The small bolus of air injected following administration of the vaccine clears the needle and prevents a localised reaction to the vaccination (19).

Preparation of LAIV

Each LAIV is supplied in a prefilled applicator for intranasal administration. The applicator contains 0.2ml of LAIV and a dose divider clip enables the vaccine to be administered as a half dose of 0.1ml into each nostril. The dose divider clip should not be removed until the first half dose has been administered.

Question 14

Vaccine administration

Accepted Answer

Administering inactivated influenza vaccines

The inactivated influenza vaccine should be administered as an intramuscular injection. For infants aged 6 months to one year, the anterolateral aspect of the thigh should be used. For those aged one year and over, the deltoid muscle in the upper arm is the preferred muscle.

Due to the presence of the adjuvant (MF59C.1), aIIV should be administered intramuscularly using a 25mm needle to enable the vaccine to be delivered into the muscle.

In larger adults, a longer length needle (for example, 38mm length) may be required for administration of flu vaccine – an individual assessment should be made.

Question 15

Checking recent flu vaccination history prior to vaccination

Accepted Answer

Influenza vaccination may be available for individuals from multiple sources. Examples include school-aged children in clinical risk groups who may receive their influenza vaccine from either a school-aged immunisation service or their primary care provider and pregnant women who may be able to receive their influenza vaccine in a maternity setting, from their primary care provider or from community pharmacies.

Prior to administering a vaccine, vaccinators should be able to assure themselves that an individual has not already received their influenza vaccination elsewhere within the current season.

Question 16

Administering inactivated influenza vaccine at the same time as other vaccines or immunoglobulins

Accepted Answer

Shingles vaccine

In line with general advice about co-administration of inactivated vaccines, the non-live shingles vaccine, Shingrix, can be given concomitantly with inactivated influenza vaccine. Initially, a 7-day interval was recommended between Shingrix and adjuvanted influenza vaccine because the potential reactogenicity from 2 adjuvanted vaccines may reduce the tolerability in those being vaccinated. Interim data from a USA study on co-administration of Shingrix with adjuvanted seasonal influenza vaccine is reassuring. Therefore, an appointment for administration of the seasonal influenza vaccine can be an opportunity to also provide shingles vaccine, although the latter should be offered all year round, rather than purely as a seasonal programme.

COVID-19 vaccine

Influenza vaccines can also be given at the same time as the COVID-19 vaccines where it is clinically indicated, operationally feasible and where the patient is content for this to happen. If the vaccines are not given together, they can be administered at any interval from each other.

RSV vaccine for older adults

There is some data which shows that in older adults, administering the RSV vaccine, Abrysvo, at the same time as seasonal influenza vaccine may reduce the immune response to the RSV vaccine. There is also data that suggests that the response to the influenza A(H3N2) component of seasonal influenza vaccine (the influenza subtype which most severely affects older adults) may be diminished when RSV and seasonal influenza vaccine are co-administered to older adults.

The clinical significance of any reduced response is unknown, but influenza immune response is known to correlate with protection against infection, and there is emerging data that RSV immune response also correlates with clinical protection. It is therefore recommended that these vaccines should not routinely be scheduled to be given at the same appointment or on the same day. No specific interval is required between administering the vaccines.

If it is thought that the individual is unlikely to return for a second appointment or immediate protection is necessary, the RSV vaccine Abrysvo can be administered at the same time as the influenza vaccine.

RSV vaccine for pregnant women

For pregnant women, the RSV vaccine Abrysvo can be given concomitantly with inactivated influenza vaccine.

General guidance about co-administration

If other vaccines are given at the same time as influenza vaccines, the vaccines should be given at separate sites, preferably in different limbs but if given in the same limb, they should be given at least 2.5cm apart and the site of each should be recorded in the patient’s record.

Because of the increased risk of local reaction following aIIV, this vaccine should be administered in a separate limb to any other vaccines that need to be given at the same time.

If any new vaccines are introduced during the influenza vaccination season, please ensure you follow the specific guidance given as to whether concomitant administration is possible for these.

Where an aIIV is given with other vaccines, including other adjuvanted vaccines, the adverse effects of both vaccines may be additive and should be considered when informing the recipient. Individuals should also be informed about the likely timing of potential adverse events relating to each vaccine.

Administering an inactivated influenza vaccine after a first dose of LAIV

In the event that all LAIV stock expires before children scheduled to receive a second dose are able to do so, a suitable inactivated injectable flu vaccine should be offered as an alternative, allowing a 4 week minimum interval period between the 2 doses

Administering LAIV

LAIV is administered by the intranasal route and is supplied in an applicator that allows 0.1ml to be administered into each nostril (total dose of 0.2ml). Clear diagrams showing administration are provided in the SmPC.

Administration of LAIV by healthcare staff in clinical risk groups

In theory, healthcare workers may have low level exposure to live attenuated influenza vaccine (LAIV) viruses during administration of the vaccine and/or from recently vaccinated patients. The vaccine viruses are cold-adapted and attenuated and are unlikely to cause symptomatic influenza. In the USA, where there has been extensive use of LAIV, no transmission of vaccine virus in healthcare settings has ever been reported and there have been no reported instances of illness or infections from the vaccine virus among healthcare professionals inadvertently exposed. The US Centers for Disease Control and Prevention (CDC) has considered that the risk of acquiring vaccine viruses from the environment is unknown but is probably low. As a precaution, however, very severely immunosuppressed individuals should not administer LAIV. Other healthcare workers who have less severe immunosuppression or are pregnant, should take reasonable precautions to avoid inhaling the vaccine and ensure that they themselves are appropriately vaccinated.

Administering LAIV when the patient has a blocked or runny nose

There are no data on the effectiveness of LAIV when given to children with a heavily blocked or runny nose (rhinitis) caused by infection or allergy. As heavy nasal congestion might impede delivery of the vaccine to the nasopharyngeal mucosa, deferral of administration until resolution of the nasal congestion or use of an appropriate alternative intramuscularly administered inactivated influenza vaccine should be considered.

Administration of both half doses in the same nostril

It is recommended that LAIV be administered as 2 divided sprays (0.1ml into each nostril) to maximise the vaccine’s contact surface area of epithelial cells within the nasopharynx. No clinical trials have been conducted using a single-nostril administration. However, there is no need to repeat immunisation as each half dose (0.1ml) contains enough viral particles to induce an immune response.

Administering LAIV with other vaccines

LAIV can be given at the same time as, or at any interval before or after other currently used vaccines, including live vaccines. If any new vaccines are introduced during the flu vaccination season, please ensure you follow the specific guidance given about concomitant administration for these.

LAIV nasal spray vaccine can be given at the same time as COVID-19 vaccines where required for eligible children. LAIV triggers an immune response in the nasal mucosa. This is unlikely to interfere with the body’s response to COVID-19 vaccines. Similarly, it is unlikely that the response to LAIV will be affected by the immune response to COVID-19 vaccine. Side effects of the nasal flu spray are very mild and short-lived and are unlikely to be in any way affected by the COVID-19 vaccine.

Administering LAIV with antiviral agents against flu

There is a potential for flu antiviral agents to lower the effectiveness of LAIV. Therefore, flu antiviral agents and LAIV should not be administered concomitantly. LAIV should be delayed for at least 48 hours after cessation of treatment with flu antiviral agents. Administration of flu antiviral agents within 2 weeks of administration of LAIV may adversely affect the effectiveness of the vaccine and an additional dose of vaccine may be required.

Administering LAIV to children with cochlear implants

Children with cochlear implants can be given LAIV safely, ideally not in the week prior to implant surgery or for 2 weeks afterwards, or if there is evidence of on-going cerebrospinal fluid leak.

Children with unrepaired craniofacial malformations

Unrepaired craniofacial malformations including cleft palate may occasionally be encountered by vaccinators immunising children of an age eligible for LAIV. The Summary of Product Characteristics notes that there is no data on use in this patient group.

Children with unrepaired craniofacial malformations where there may be a potential portal of entry to the brain or central nervous system, or where there are particular concerns around absorption may require an IIV injection instead.

Question 17

Adverse reactions

Accepted Answer

As with all vaccines and other medicines, healthcare professionals and patients are encouraged to report suspected adverse reactions to influenza vaccines using the Yellow Card reporting scheme. The black triangle symbol (▼) is used as a reminder to healthcare professionals and the public to report all suspected side-effects to the Medicines and Healthcare Products Regulatory Agency (MHRA) using the Yellow Card scheme. Five of the 7 vaccines available for 2025 to 2026 have a black triangle symbol.

Fever following inactivated flu vaccine

Vaccinated individuals, parents and carers should be advised that inactivated flu vaccines may cause a mild fever which usually resolves within 48 hours. This is a common, expected reaction.

Feeling generally unwell, shivery, achy and tired and injection site reactions such as redness, swelling and tenderness are also commonly reported symptoms following vaccination with inactivated flu vaccine. These symptoms usually disappear within 1 to 2 days without treatment but paracetamol can be given if necessary to relieve any of these symptoms.

As has always been recommended, any fever after vaccination should be monitored and if individuals, parents or carers are concerned about their, or their child’s health at any time, they should seek advice from their GP or NHS 111.

Fever following LAIV

The nasal spray influenza vaccine may cause a runny or blocked nose, reduced appetite, feeling generally unwell and headache. These symptoms usually disappear within 1 to 2 days without treatment, but paracetamol can be given if necessary. Studies have found that the likelihood of children presenting with a fever after receiving the influenza nasal spray is similar to that in the general population, that is, children of the same age who have not received LAIV are just as likely to present with a fever.

Adverse reactions following administration of inactivated flu vaccine

Commonly reported reactions following administration of inactivated influenza vaccine include malaise, low grade fever, headache, fatigue, myalgia, arthralgia and redness, swelling and pain at the injection site. Immediate reactions such as urticaria, angio-oedema, bronchospasm and anaphylaxis can occur but are rare.

The vaccine manufacturer reports in the product SmPC for aIIV that in clinical trials, the incidence of both local and systemic reactions following immunisation with the adjuvanted influenza vaccine was higher than the incidence of reactions following non-adjuvanted flu vaccines. The SmPC for IIV-HD states that the reactogenicity of the IIV-HD vaccine was slightly increased compared to the standard dose vaccine, but that no major difference in intensity was observed. Both IIVc and IIVr are reported to be well tolerated with a similar safety profile to egg-cultured flu vaccines (IIVe).

Adverse reactions following administration of LAIV

Nasal congestion and/or runny nose (rhinorrhoea), reduced appetite, malaise and headache are common adverse reactions following administration of LAIV. Hypersensitivity reactions such as urticaria, facial oedema, bronchospasm and anaphylaxis can occur rarely.

Question 18

Common issues

Accepted Answer

Common issues (CI) relating to influenza vaccination are listed and described below.

CI1 Patients who are acutely unwell when presenting for vaccination

CI2 Vaccination of individuals recently diagnosed with influenza infection

CI3 Vaccination of patients recently diagnosed with COVID-19 infection

CI4 Vaccination of individuals experiencing prolonged COVID-19 symptoms (‘Long COVID’)

CI5 Uncertainty regarding previously administered dose of influenza vaccine

CI6 Patients who have already received an influenza vaccine during early 2025

CI7 Individuals who have inadvertently been given a flu vaccine that is not the one recommended for their age group

CI8 Inadvertent administration of aIIV to a pregnant or breastfeeding woman who is aged 50 years or over

CI9 Inadvertent administration of LAIV to a young person who is pregnant or breastfeeding

CI10 Patients under 65 years of age at time of vaccination but who will be 65 years old by 31 March 2026

CI11 Administration of flu vaccine earlier than the recommended start of programme

CI12 Administering an incomplete dose of inactivated influenza vaccine or LAIV

CI13 Inadvertent administration of an extra dose of influenza vaccine

CI14 Inadvertent administration of expired doses of vaccine

CI15 Inadvertent administration of LAIV to a child who is aged less than 24 months

CI16 Inadvertent administration of LAIV to an adult

CI17 Immunosuppression and inactivated influenza vaccine

CI18 Inadvertent administration of LAIV to a child who is immunosuppressed

CI19 Patients taking steroid medication

CI20 Patients taking checkpoint inhibitors

CI21 Sneezing, nose blowing and nasal dripping following administration of LAIV

CI22 LAIV mist contact with the eye

CI23 Vaccination of patients taking anticoagulants or with a bleeding disorder

CI24 Guillain-Barré Syndrome (GBS) and influenza vaccine

CI25 Porcine gelatine

CI26 History of allergy to canine allergens

CI27 Patients requesting live intranasal influenza vaccine (LAIV) instead of an inactivated injected vaccine due to needle phobia

CI1. Patients who are acutely unwell when presenting for vaccination

Vaccination may be postponed in those who are acutely unwell until they have fully recovered. This is to avoid confusing the differential diagnosis of any acute illness by wrongly attributing any signs or symptoms to the adverse effects of the vaccine.

CI2. Vaccination of individuals recently diagnosed with influenza infection

Individuals eligible to receive the influenza vaccine should have it even if they have recently had confirmed influenza infection. Having the vaccine will help to protect against other circulating flu strains. Both the inactivated influenza vaccine and the LAIV can be given at any time following recovery providing there are no contraindications to vaccination and the patient is not acutely unwell.

CI3. Vaccination of patients recently diagnosed with COVID-19 infection

Patients eligible to receive NHS-funded influenza vaccine but recently diagnosed with COVID-19 infection can be vaccinated when recovered. Patients and vaccinators should refer to the GOV.UK coronavirus pages to ensure recommendations that are current at the time of vaccination are followed. The COVID-19 vaccination programme collection page also contains information for healthcare practitioners.

CI4.Vaccination of individuals experiencing prolonged COVID-19 symptoms (‘Long COVID’)

Having prolonged COVID-19 symptoms (‘Long COVID’) is not a contraindication to receiving influenza vaccine, but if there is evidence of current deterioration, deferral of influenza vaccination may be considered to avoid incorrect attribution of any change in the person’s underlying condition to the influenza vaccine.

If their symptoms are stable however and they are eligible to receive influenza vaccination, it would be recommended in order to avoid compounding their COVID-19 symptoms with flu symptoms.

CI5. Uncertainty regarding previously administered dose of influenza vaccine

If there is no documented evidence of an eligible patient having received an influenza vaccine during the current flu season then they should be offered a dose. If they have already had a vaccine this flu season, an additional dose is unlikely to cause any harm. Any adverse reactions to an extra dose are likely to be similar to those commonly seen after a first dose of influenza vaccine such as local redness and/or pain at the injection site and malaise.

CI6. Patients who have already received an influenza vaccine during early 2025

If a patient received the vaccine produced for the 2024 to 2025 flu season in the first few months of 2025, then they will still need a dose of the vaccine produced for the 2025 to 2026 season as it contains different viruses to protect against other influenza strains (one of the flu A strains is different in the 2025 to 2026 vaccine ).

In addition, the protection gained from influenza vaccine is only thought to last for one season so those eligible to receive the vaccine are recommended to have it every season to ensure on-going protection.

If an eligible patient has received a vaccine in 2025 formulated for the southern hemisphere (for example because they were in Australia or New Zealand during the flu season there), and they will be in the UK (northern hemisphere) over winter 2025 to 2026, they should receive another dose of vaccine in the UK as their protection may have waned, particularly if they are an older adult.

Further information on the composition of influenza vaccines is published on the WHO global influenza programme webpage.

CI7. Individuals who have inadvertently been given a flu vaccine that is not the one recommended for their age group

If an individual has inadvertently received a flu vaccine different to the one recommended for their age group, they should be informed of the error and the potential implications of this error.

Individuals aged 65 years and over (particularly those more than 75 years of age) may not respond as well to the IIVe as they would to the vaccines recommended for their age group (aIIV, IIV-HD, IIVr or second line IIVc). As data has shown IIVe can offer minimal protection for this age cohort in some seasons, revaccination should ordinarily be offered and individuals should be advised of the benefits and risks of this. There is clear benefit in the additional protection that is likely to be offered by giving the correct vaccine. However, they should also be alerted to the potential increased risk of a local or systemic reaction to a subsequent dose of the recommended flu vaccine for their age.

Although there is no trial data available on the safety and effectiveness of administering IIVe followed shortly by aIIV, this advice is based on general principles of vaccination and experience of influenza revaccination following cold chain and administration incidents. It is also based on trial data showing that older adults did not experience many reactions following a 2-dose adjuvanted pandemic vaccination course given after unadjuvanted seasonal influenza vaccine. This trial showed that side effects were less common than amongst younger adults given the same regimen, and that giving two doses of adjuvanted trivalent seasonal influenza vaccine to older adults had a similarly acceptable reactogenicity profile (20). Similar reactogenicity is anticipated if aIIV, IIV-HD or IIVr is given as a replacement for the IIVe given inadvertently.

For adults aged 65 years or older but at the younger end of the range, and without the medical conditions which are considered risk factors for severe influenza infection or influenza complications, the benefits of revaccination may be lower and the reactogenicity higher.

If a decision is made to offer the vaccine the individual should have received, it is ordinarily recommended that this is done as soon as possible after the first dose was given and ideally within a week. This will enable protection to be made as soon as possible. It can still be given if more than a week has elapsed however and this decision may depend on the level of flu activity at the time.

If an individual under 50 years of age is given aIIV in error, they will not require revaccination. Studies (21, 22) have looked at the immunogenicity and reactogenicity of this vaccine compared to non-adjuvanted influenza vaccine in the 18- to 64-year-old age group. These have found that the adjuvanted vaccine was highly immunogenic with good levels of protection achieved. Reporting of local reactions (pain and warmth at the injection site) and systemic reactions (chills and aching muscles) was higher than in older age groups and when compared to those who received an unadjuvanted vaccine. Where the aIIV has been inadvertently administered to people in the 18- to 49-year age group, they should be informed that they may be more likely to develop a reaction following the aIIV than following previous influenza vaccinations. However, the studies showed that in those who experienced reactions, these generally occurred within 3 days of vaccination and were mild, transient and self-resolving.

If an individual aged under 60 years is given IIV-HD in error, they will also not require revaccination as it is expected that they will make a good immune response to this vaccine. However, they should be informed that they may be more likely to experience adverse reactions (injection site pain, myalgia, headache and/or malaise) than following a standard dose influenza vaccine.

CI8. Inadvertent administration of aIIV to an individual who is pregnant or breastfeeding aged 50 years or over

While aIIV is licensed from 50 years of age, it is not indicated in women who are, or may be, pregnant or breastfeeding. Where aIIV has been inadvertently administered to an individual aged 50 years or over who is pregnant or breastfeeding, the individual will not require revaccination.

Although there is no trial data available on administration of aIIV to individuals who are pregnant or breastfeeding, animal studies do not indicate any harmful effects. As aIIV is an inactivated influenza vaccine, there are no known risks for women who are vaccinated at any stage of pregnancy or shortly before conception.

CI9. Inadvertent administration of LAIV to a young person who is pregnant or breastfeeding

While the administration of LAIV to a pregnant woman is not recommended nor licenced, in the event that it is inadvertently administered to a young person who is pregnant, they will not require revaccination.

There is no evidence of risk when LAIV has been administered during pregnancy (12). The live viruses in LAIV have been attenuated (weakened) and adapted to cold so that they can only replicate at the lower temperatures found in the nasal passage. These live viruses cannot replicate efficiently elsewhere in the body and therefore there is no theoretical basis for concern about infection of the unborn foetus or the mother’s lungs. IIVs are, however, preferred for those who are pregnant. The available evidence indicates that LAIV viruses are not excreted in breastmilk.

CI10. Patients under 65 years of age at time of vaccination but who will be 65 years old by 31 March 2026

Patients who are not in a clinical risk group (and therefore would be otherwise eligible), who will become 65 years of age by 31 March 2026 but who are aged 64 years at the time of vaccination are eligible for vaccination and can receive aIIV, IIV-HD or IIVr in accordance with the national influenza immunisation programme for 2025 to 2026.

CI11. Administration of influenza vaccine earlier than the recommended start of programme

While seasons can start early (such as in 2003 with circulation of a reassortment A(H3N2)), the potential impact of in-season waning of vaccine protection in adults (particularly older adults) also needs to be considered. This suggests that the optimal timing of immunisation for adults may be later than previously recommended. Available data does not indicate equivalent waning in children, supporting vaccination of children from the earliest availability of the vaccines in September. JCVI has advised that the adult vaccination programme start of October, with the exception of pregnant women (JCVI 10 October 2023). This is because the latest scientific evidence shows that protection from the influenza vaccine is better in the 14 to 90 day period than from 91 days or more after vaccination, particularly in older adults.

Following clinical assessment, there may be a small number of other adults for whom it would be better not to delay influenza vaccination until October. For example, for those who are due to commence immunosuppressive treatment (such as chemotherapy) before October, having influenza vaccine before they start treatment would allow them to make a better response to their vaccination. GPs should use clinical judgement to bring forward vaccination in exceptional circumstances, as outlined in the Green Book, and offer vaccination as soon as vaccine comes available in line with contractual arrangements.

Some special educational needs (SEN) schools cater for individuals up to 25 years of age. Any young person over 17 years of age in a clinical risk group and in a SEN school can be vaccinated alongside their peers, using LAIV. Due to clinical vulnerability, school aged immunisation teams usually prioritise SEN settings for vaccination in early September – at the beginning of the vaccination season, which will be before the vaccination programme for individuals over the age of 18 years in clinical risk groups commences in October. Vaccination of all children and young people in SEN settings from 1 September is advised, even if a young person is over 17 years of age. LAIV off-label should be used in this cohort (if not otherwise clinically contraindicated). Young people are not expected to lose protection as rapidly as the elderly population and therefore offering vaccination early in the season, alongside their peers, will still offer protection to young people in peak season. As flu circulation in children normally precedes that in adults, vaccinating all children, and young people in SEN settings over 17 years of age alongside their peers will protect them in the event of flu exposure in the setting early in the season and may also reduce anxiety by enabling them to be vaccinated in a familiar setting. Further information is available in the Green Book chapter 19.

In general, where adults have inadvertently been vaccinated prior to October, if the vaccine was administered between September and October, revaccination is not recommended as the benefit in vaccine effectiveness of vaccination one month later at an individual level is likely to be small and needs to be balanced against the small risk of adverse reactions. Where there is a clinical concern that the individual may be less likely to develop a sustained immune response to vaccination, for example due to immunosuppression, a clinical decision may be made to revaccinate. If the vaccine was administered prior to September, a second dose is recommended from October onwards and at least 3 months after the first dose (by which time there is likely to have been waning of the first dose).

CI12. Administering an incomplete dose of inactivated influenza vaccine or LAIV

If it is thought that the patient did not receive a full dose of injected inactivated influenza vaccine (for example, because some spilt out whilst administering the vaccine), it is recommended that the dose is repeated. This can be at any interval from the partial dose already given. Giving it the same day or within the next few days will enable protection to be made as soon as possible. The patient should be informed there may be a potential risk of local and systemic reactions from a repeat dose.

An incomplete dose of LAIV does not need to be repeated as long as at least 0.1ml of the vaccine has been given intranasally as each half dose (0.1ml) contains enough viral particles to induce an immune response (23).

Cl13. Inadvertent administration of an extra dose of influenza vaccine

Any adverse reactions to an extra dose are likely to be similar to those commonly seen after a scheduled first dose of influenza vaccine such as local redness and/or pain at the injection site, malaise, and so on. The patient should be advised of this and offered reassurance that children in clinical risk groups under the age of 9 years who have never received influenza vaccine in previous years are specifically recommended to have 2 doses 4 weeks apart. Local systems should be reviewed to prevent this happening again.

CI14. Inadvertent administration of expired doses of vaccine

Inadvertently administering an expired dose of inactivated influenza vaccine or LAIV is unlikely to cause harm other than that the expired dose may not offer adequate protection. Healthcare practitioners should inform the patient, parent or carer of the error, provide reassurance where necessary and discount the expired dose. An additional dose of an age appropriate influenza vaccine that is in date should be offered as soon as possible (on the same day as the expired vaccine was given or as soon as the error is discovered), to ensure satisfactory protection. There is no minimum interval between an expired and a valid dose of influenza vaccine as it is the same product being administered. In the event that a repeat dose of LAIV is required and ‘in date’ LAIV is not available, a suitable inactivated influenza vaccine should be offered as an alternative (preferably IIVc).

Inadvertently administering an expired dose of inactivated influenza vaccine/LAIV is a clinical incident that should be reported via the local governance system(s), so that appropriate action can be taken.

CI15. Inadvertent administration of LAIV to a child who is aged less than 24 months

LAIV is not currently licensed or recommended in children aged less than 24 months. An increase in wheezing and hospitalisation in children aged from 6 to 23 months of age was observed in clinical trials. The decision not to license the vaccine for use in children aged less than 24 months was based on these observations rather than vaccine efficacy in this age group. It should be noted that in subgroup analysis, the majority of these events occurred in children aged less than 12 months.

Children who have received LAIV at less than 24 months of age do not require a replacement dose. The inadvertently administered vaccine should count as a valid dose as LAIV will provide protection in this age group. However, the child’s parents or carers should be informed of the possible adverse events in the short term and advised to seek medical care if adverse events occur. They should be reassured that no long-term effects from receiving LAIV are anticipated.

Children from 6 months of age in clinical risk groups who have not received an influenza vaccine previously should count the inadvertently administered LAIV as the first dose. The child should also be offered the inactivated influenza vaccine 4 weeks later to complete the 2 dose schedule (in line with the recommendation that children in clinical risk groups aged 6 months to under 9 years who have not received inactivated influenza vaccine previously should be offered a second dose at least 4 weeks after the first dose). If the child reaches their second birthday in the 4 weeks between the dose of LAIV and when a second dose of influenza vaccine would be due, a further dose of LAIV can be given (if not contraindicated).

Healthcare professionals should report the administration error via their local governance systems so that lessons can be learned and the risk of future errors minimised.

CI16. Inadvertent administration of LAIV to an adult

The patient group in whom inadvertent administration of LAIV is most likely to occur may be 18-year-old pupils in school, who may be vaccinated as part of a commissioned service for children with medical risk factors for severe influenza, age 16 or 17 years, where such a service may be offered alongside school-based clinics for the programme for younger children with and without medical risk factors.

In the UK, LAIV is only licensed for use in children from 24 months to less than 18 years of age, however in the USA, LAIV is licensed for use in adults up to 49 years of age. The evidence from a systematic review of trials shows protection declines with increasing age. However, there is no concern with protection in younger adults. There is no need for a further vaccination in young adults inadvertently given LAIV. For adults aged 30 years and older, revaccination should be considered following risk assessment including due regard for whether or not a person is in a clinical risk group for influenza.

See also advice in this guidance on LAIV in pregnancy if applicable, and LAIV where this is specifically sought for vaccination of an adult.

CI17. Immunosuppression and inactivated influenza vaccine

Inactivated influenza vaccines can be safely given to immunosuppressed individuals though they may make a suboptimal response to the vaccine.

Individuals may be immunosuppressed because of a medical condition or because of medical therapy that they are taking or receiving, and immunosuppression may continue for several months following completion of treatment. As these patients are at risk of increased morbidity and mortality if they develop influenza, it is important that they are offered influenza vaccination. Although the recommended timing of when influenza vaccines should be offered to adults has been changed to from October onwards , there may be a small number of other adults, following clinical assessment, for whom it would be better not to delay influenza vaccination until October. For example, for those who are due to commence immunosuppressive treatment (such as chemotherapy) before October, having influenza vaccine before they start treatment would allow them to make a better response to their vaccination. GPs should use clinical judgement to bring forward vaccination in exceptional circumstances, as outlined in the Green Book influenza chapter, and offer vaccination as soon as vaccine becomes available in line with contractual arrangements. For individuals due to commence immunosuppressive treatments, inactivated vaccines should ideally be administered at least 2 weeks before commencement. In some cases, this will not be possible and therefore vaccination may be carried out at any time.

If there is any uncertainty regarding an individual’s level of immunosuppression, further advice should be taken from their consultant. Further advice regarding vaccination of immunosuppressed individuals can be found in Chapter 7 of the Green Book.

Close/household contacts of immunocompromised individuals are also eligible to receive NHS-funded influenza vaccination.

CI18. Inadvertent administration of LAIV to a child who is immunosuppressed

If an immunosuppressed individual receives LAIV then the degree of immunosuppression should be assessed. If the individual is severely immunosuppressed, antiviral prophylaxis should be considered. Otherwise, they should be advised to seek medical advice if they develop flu-like symptoms in the 4 days (the usual incubation period) following administration of the vaccine. If antivirals are used for prophylaxis or treatment, then in order to maximise their protection in the forthcoming flu season, the patient should also be offered inactivated influenza vaccine. This can be given straight away.

Healthcare professionals should report the administration error via their local governance systems so that the appropriate action can be taken, lessons can be learned and the risk of future errors minimised.

CI19. Patients taking steroid medication

Patients taking steroids can be safely vaccinated with inactivated influenza vaccine. As systemic steroids at a dose equivalent to prednisolone 20mg or more per day are considered to be immunosuppressive, patients taking steroids are at risk of serious illness if they develop flu and so should be vaccinated. Patients who are receiving high-dose steroids may be immunosuppressed for at least 3 months after cessation of treatment. Also refer to the immunosuppression section.

LAIV should not be given to children taking high dose corticosteroids or who require regular oral steroids for maintenance of asthma control. These children should be given a suitable inactivated influenza vaccine instead (preferably IIVc).

CI20. Patients taking checkpoint inhibitors

There is no evidence of an association between the squalene adjuvant used in aIIV and autoimmune disease, or of any enhanced risk of autoimmune disease in those who are given checkpoint inhibitors and receive the adjuvanted influenza vaccine (aIIV). The national flu vaccination policy therefore still applies for use of the recommended inactivated influenza vaccinations. The IIVc, IIVr and IIV-HD vaccines do not contain an adjuvant and these should be used if there is a decision by the individual’s clinician to use an alternative to an adjuvanted vaccine in those on checkpoint inhibitors.

CI21. Sneezing, nose blowing and nasal dripping following administration

If the child sneezes, blows their nose or has nasal dripping following administration of LAIV, the vaccine dose does not need to be repeated. Binding of the virus to epithelial cells occurs very rapidly and there are more virus particles in the vaccine than are needed to establish immunity. Therefore, sneezing or blowing the nose immediately after immunisation with LAIV will not affect immunity (24) and reassurance should be given that the vaccine will still be effective if any of these occur.

There is no evidence that crying or screaming is aerosol generating, and coughing and sneezing, which may occur following administration of LAIV, are not high-risk aerosol generating procedures.

Immunisers should follow the recommendations for personal protective equipment (PPE) which are current at the time of delivering the influenza vaccines.

CI22. LAIV mist contact with the eye

If the vaccine is accidentally squirted into the child’s eye, it may cause some slight irritation to the eye and eyewash or normal saline should be used to wash out the eye. The child or parent or carer should be advised to seek medical advice if any irritation occurs and persists beyond what might reasonably be expected.

CI23. Vaccination of patients taking anticoagulants or with a bleeding disorder

There is a lack of evidence that the subcutaneous route of vaccination is any safer than the intramuscular route in people taking anticoagulants. The subcutaneous route can itself be associated with an increase in localised reactions.

Individuals on stable anticoagulation therapy, including individuals on warfarin who are up-to-date with their scheduled INR testing (international normalised ratio, this is a measure of the time it takes for blood to clot) and whose latest INR was below the upper threshold of their therapeutic range, can receive intramuscular vaccination. If in any doubt, consult with the clinician responsible for prescribing or monitoring the individual’s anticoagulant therapy.

Individuals with bleeding disorders may be vaccinated intramuscularly if, in the opinion of a doctor familiar with the individual’s bleeding risk, vaccines or similar small volume intramuscular injections can be administered with reasonable safety by this route. If the individual receives medication or treatment to reduce bleeding, for example treatment for haemophilia, intramuscular vaccination can be scheduled shortly after such medication or treatment is administered.

A fine needle (equal to 23 gauge or finer calibre such as 25 gauge) should be used for the vaccination of these patient groups, followed by firm pressure applied to the site (without rubbing) for at least 2 minutes, (25) and the individual, parent, carer should be informed about the risk of haematoma from the injection.

The cell-cultured inactivated influenza vaccine (IIVc), recombinant inactivated influenza vaccine (IIVr) and adjuvanted inactivated influenza vaccines (aIIV) are not licensed for subcutaneous administration so should only be administered intramuscularly (as per advice above). If these vaccines are given subcutaneously in error, they do not need to be repeated but the vaccinated individual should be warned of the increased risk of local reactions at the injection site .

CI24. Guillain-Barré Syndrome (GBS) and influenza vaccine

Previous GBS is not a contraindication to influenza vaccination. A UK study found that there was no association between GBS and influenza vaccines although there was a strong association between GBS and influenza-like illness. Stowe and others reported that a causal relationship between immunisation with influenza vaccine and GBS has not been established (26).

CI25. Porcine gelatine

LAIV contains a highly processed form of gelatine (derived from pigs) as one of its additives. Gelatine is commonly used in a range of pharmaceutical products, including many capsules and some vaccines. The gelatine in LAIV is used as a stabiliser to protect the live viruses from the effects of temperature.

The gelatine used in live vaccines is highly purified and hydrolysed (broken down by water), so it is different from the gelatine used in foods. Very sensitive scientific tests have shown that no DNA from pigs can be detected in LAIV. These tests show that the gelatine is broken down so much that the original source cannot be identified.

Some people, including members of Muslim or Jewish religious communities may be concerned about using vaccines that contain gelatine from pigs (porcine gelatine). The following statement from representatives of the Jewish community may help some patients, parents or carers to reach a decision about having the vaccine.

Rabbi Abraham Adler from the Kashrus and Medicines Information Service said: “It should be noted that according to Jewish laws, there is no problem with porcine or other animal derived ingredients in non-oral products. This includes vaccines, including those administered via the nose, injections, suppositories, creams and ointments”.

However, it is acknowledged that some groups within the British Muslim community may consider the porcine-containing product to be forbidden. The final decision about whether parents have their child vaccinated is with them. In order to come to an informed decision, they should be able to consider the evidence about the advantages and disadvantages of the vaccination. The British Islamic Medical Association (BIMA) have produced resources which explain the benefits of flu vaccination, the Islamic position on taking up the vaccine, and how parents can weigh up whether their children should have the nasal spray vaccine given the porcine gelatine content and conflict with a halal diet. Resources can be downloaded from the British Islamic Medical Association.

Children whose parents refuse LAIV due to the porcine gelatine content can be offered an inactivated influenza vaccine. Vaccine (IIVc) for this cohort is available to order by General Practice and school aged immunisation teams via ImmForm.

CI26. History of allergy to canine allergens

The original cells used in the Madin-Darby Canine Kidney (MDCK) cell line in which the flu vaccine viruses used in IIVc are grown were taken by Madin and Darby from the kidney tubule of an adult dog in 1958. This is the cell line that is still used today. It is a continuous cell line where the cells have adapted to grow and divide continually with unlimited availability so the cell-cultured manufacturing process does not require any new cells to be taken.

After the vaccine viruses are grown, they are highly purified and this purification process removes the cell culture materials. It is extremely unlikely that any cell culture material remains in the vaccine (the risk of a dose of the final vaccine product containing an intact MDCK cell is calculated to be less than 1 per 10³⁴ doses (27).

The MDCK cell line is used because the influenza virus grows well in it, it is able to produce high volumes of influenza virus for use in vaccines and the influenza virus isolated following culture in these cells retains the antigenic properties of the original strain. So, this method of vaccine virus production should result in the vaccine virus being a closer match to the wild-type circulating influenza viruses.

A history of hypersensitivity to canine allergens is not listed as a contraindication or precaution to immunisation with IIVc. MDCK cells do not express known major canine allergens associated with hypersensitivity reactions, however minor canine allergens may be present, posing a hypothetical concern about the possibility of hypersensitivity reactions. In clinical trials (totalling over 10,000 participants), none of the participants who reported a dog allergy reported any hypersensitivity reactions following administration of IIVc. There was no indication of any increased incidence in immediate local or systemic reactions in those who received IIVc compared to those who received an egg-cultured influenza vaccine or who were in the placebo groups. If there is significant concern, patients can be given IIVr or an egg-cultured vaccine instead (as appropriate to age).

CI27. Patients requesting live intranasal influenza vaccine (LAIV) instead of an inactivated injected vaccine due to needle phobia

Patients for whom the inactivated injected vaccine is recommended should be encouraged, where possible, to have the inactivated injected vaccine.

UKHSA procures LAIV and distributes this to general practices, who vaccinate 2 and 3 year olds and children in at risk groups, and to providers responsible for vaccinating children in school. LAIV is licensed for children aged 2 to 17 years of age. It is not licensed in adults because there is some evidence of poorer efficacy in this age group when compared with the inactivated influenza vaccines.

UKHSA does not supply flu vaccine to occupational health departments, pharmacies or GP practices for adult patients.

However, in exceptional circumstances, individual medical practitioners may choose to use their stocks of LAIV ‘off-label’ to vaccinate patients with a needle phobia.

It is envisaged that the type of patient who would be offered this might be someone with learning disabilities who becomes seriously distressed about needles. This is part of the requirement that the NHS has to make reasonable adjustments to accommodate the needs of a person with learning disabilities. See Flu vaccinations: supporting people with learning disabilities for more information.

Others who might also be offered LAIV include people in a clinical risk group with a serious needle phobia who may otherwise go unimmunised if they refuse to have an injected inactivated vaccine.

The legislation does allow for such situations and the Medicines and Healthcare products Regulatory Agency state that “there are clinical situations when the use of medicines outside the terms of the licence (that is, ‘off-label’) may be judged by the prescriber to be in the best interest of the patient on the basis of available evidence” (28). The responsibility for such use rests with the health professional. In this situation, a Patient Specific Direction (PSD) will be required. In these exceptional circumstances, where it has not proved possible to administer the inactivated vaccine, UKHSA has agreed that the national LAIV stock can be used for this purpose.

Question 19

Useful links

Accepted Answer

Green Book Influenza chapter

Letters detailing 2025 to 2026 flu programme and other important documents relating to the flu vaccine programme

Leaflets, posters, training slides and additional flu resources prepared specifically to support the annual flu programme

Paper copies of UKHSA resources can ordered for free to be delivered to you from Health Publications

Flu vaccination: easy read resources

NHS England Public Health Commissioning information

General practice specifications for seasonal influenza immunisation

Summary of product characteristics (SmPC) and patient information leaflet (PIL) for flu vaccines

Flu immunisation PGD templates (note: these PGDs require authorisation before use)

Written Instruction for the administration of seasonal flu vaccination

e-learning programme

ImmForm website for ordering child flu vaccines (requires username and password)

UKHSA annual flu programme home page

DHSC Campaign Resource Centre (free registration required)

Vaccine Knowledge Project. Inactivated Flu Vaccine

Joint Committee on Vaccination and Immunisation

National Institute for Health and Care Excellence (NICE) guidelines on increasing influenza vaccine uptake

WHO recommendations for influenza vaccine composition

A video for health professionals on how to administer LAIV produced by NHS Education for Scotland

Note: this video was made when Fluenz Tetra was in use but although the name of the vaccine has changed to reflect the reformulation of the vaccine from a quadrivalent vaccine to a trivalent vaccine, the method of administration shown in the video is unchanged. Note however, that the expiry date is now 15 weeks from production.

AstraZeneca How to administer the Fluenz nasal spray flu vaccine video

Toolkit for childhood flu programme

Community Pharmacy Seasonal Influenza Vaccination Advanced Service

Flu vaccine uptake figures

Vaccine update – UKHSA monthly newsletter

Question 20

References

Accepted Answer

1. Pitman R Nagy L and Sculpher M. ‘Cost-effectiveness of childhood influenza vaccination in England and Wales: Results from a dynamic transmission model’. Vaccine 2013: volume 31, issue 6, pages 927 to 942

2. Pebody R, Sinnathamby M, Warburton F and others. ‘Uptake and impact of vaccinating primary school-age children against influenza: experiences of a live attenuated influenza vaccine programme, England, 2015 to 2016’. Eurosurveillance, 21 June 2018: volume 23, issue 25

3. Sinnathamby M, Warburton F, Reynolds A and others. ‘An intercountry comparison of the impact of the paediatric live attenuated influenza vaccine (LAIV) programme across the UK and the Republic of Ireland (ROI), 2010 to 2017’. Influenza Other Respir Viruses. 13 February 2023: volume 17, issue 2

4. Joint Committee on Vaccination and Immunisation. ‘Statement on the annual influenza vaccination programme – extension of the programme to children’. JCVI, 25 July 2012

5. Pierce M, Kurinczuk J, Spark P and others. ‘Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study’. British Medical Journal 2011: page 342:d3214

6. McNeil SA, Dodds LA, Fell DB and others. ‘Effect of respiratory hospitalization during pregnancy on infant outcomes’. American Journal of Obstetrics and Gynecology June 2011: volume 204, issue 6, supplement, S54-S57

7. Omer SB, Goodman D, Steinhoff MC and others. ‘Maternal influenza immunization and reduced likelihood of prematurity and small for gestational age births: a retrospective cohort study’. PLOS Medicine 31 May 2011: volume 8, issue 5, e1000441

8. Neuzil KM, Reed GW, Mitchel EF and others. ‘Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women’. American Journal of Epidemiology 1998: volume 148, issue 11, pages 1,094 to 1,102

9. Pebody R, McClean E, Zhao H and others. ‘Pandemic influenza A (H1N1) 2009 and mortality in the United Kingdom: risk factors for death, April 2009 to March 2010’. Eurosurveillance 20 May 2010: volume 15, issue 20

10. Vousden N, Bunch K, Knight M and others. ‘Incidence, risk factors and impact of seasonal influenza in pregnancy: A national cohort study.’ PLOS ONE January 2021: volume 16, issue 1, e0244986

11. Tamma PD, Ault KA, del Rio C and others. ‘Safety of influenza vaccination during pregnancy’. American Journal of Obstetrics and Gynecology 2009: volume 201, issue 6, pages 547 to 552

12. Toback SL, Beigi R, Tennis P and others. Maternal outcomes among pregnant women receiving live attenuated influenza vaccine. Influenza and Other Respiratory Viruses. 2012 Jan, volume 6, issue 1, pages 44 to 51

13. WHO ‘Recommended composition of influenza virus vaccines for use in the 2025-2026 northern hemisphere influenza season. 28 February 2025

14. Joint Committee on Vaccination and Immunisation. ‘Minutes of the February 2015 meeting’

15. Personal communication from Seqirus, 8 June 2018

16. Joint Committee on Vaccination and Immunisation. Advice on influenza vaccines for 2025/26

17. Personal communication from Seqirus 7 May 2019

18. Approval Letter: influenza virus vaccine live, intranasal. US Food and Drug Administration archive. June 17 2003

19. Crisp J and Taylor C. Potter and Perry’s Fundamentals of Nursing. 2005 (Second edition). Australia: Elsevier. Cited in Floyd S. ‘Administering the influenza vaccine: what is best practice for administering the influenza vaccine? Some techniques are safer than others.’ The Free Library 2010. New Zealand Nurses’ Organisation

20. Vesikari T, Forstén A, Herbinger KH , Della Cioppa G, Beygo J, Borkowski A , Groth N, Bennati M, von Sonnenburg F. Safety and immunogenicity of an MF59®-adjuvanted A/H5N1 pre-pandemic influenza vaccine in adults and the elderly. Vaccine February 2012: volume 30, issue 7 pages 1,388 to 1,396

21. Frey S, Poland G, Percell S and others. ‘Comparison of the safety, tolerability, and immunogenicity of a MF59-adjuvanted influenza vaccine and a non-adjuvanted influenza vaccine in non-elderly adults’. Vaccine 1 October 2003: volume 21, issues 27 to 30, pages 4,234 to 4,237

22. Reisinger K, Holmes S, Pedotti P and others. ‘A dose-ranging study of MF59®-adjuvanted and non-adjuvanted A/H1N1 pandemic influenza vaccine in young to middle aged and older adult populations to assess safety, immunogenicity, and antibody persistence one year after vaccination’. Human Vaccines and Immunotherapeutics May 2014: volume 10, issue 8, pages 2,395 to 2,407

23. Astra Zeneca. FLUMIST® (Influenza Vaccine [Live, attenuated]) – Single nostril Administration/Inadvertent Single Nostril Administration [Internet] Message to: British Columbia Centre for Disease Control. July 30 2013. Cited in British Columbia Centre for Disease Control. Administration of Quadrivalent Live Attenuated Influenza Vaccine Revised June 2022

24. Public Health Agency of Canada [Internet]. Ottawa (ON): Public Health Agency of Canada. Recommendations on the use of live, attenuated influenza vaccine (FluMist®). Supplemental statement on Seasonal Influenza Vaccine for 2011-12. 2011. Cited in British Columbia Centre for Disease Control.. Administration of Quadrivalent Live Attenuated Influenza Vaccine Revised June 2022

25. Centers for Disease Control and Prevention. Vaccine recommendations and guidelines of the ACIP. Vaccinating Persons with Increased Bleeding Risk. Last reviewed June 2023

26. Stowe J, Andrews N, Wise L and others ‘Investigation of the temporal association of Guillain-Barre syndrome with influenza vaccine and influenza like illness using the UK General Practice Research Database’. American Journal of Epidemiology February 1 2009: volume 169, issue 3, pages 382 to 388

27. Gregersen JP, Schmitt HJ, Trusheim H and others. ‘Safety of MDCK cell culture-based influenza vaccines’. Future Microbiology February 2011: volume 6, issue 2, pages 143 to 152

28. Medicines and Healthcare Products Regulatory Agency. ’Off-label or unlicensed use of medicines: prescribers’ responsibilities.’ 11 December 2014

IIVe is suitable to offer to these children as a second option if IIVc not available but it has not been procured by UKHSA and so cannot be ordered from ImmForm. ↩ ↩² ↩³
In special educational needs (SEN) settings, some children and young people may be in attendance up to 25 years of age. Individuals 18 years and over attending a special education needs (SEN) school and who are in a clinical risk group may also be vaccinated alongside their peers. LAIV off-label should be used in this cohort (if not otherwise clinically contraindicated). ↩

Eligible group	Type of influenza vaccine
Children in a clinical risk group aged from 6 months to less than 2 years	Offer IIVc ^{[footnote 1]}
Children in a clinical risk group aged 2 to under 18 years	Offer LAIV If LAIV is contraindicated (or it is otherwise unsuitable) offer IIVc ^{[footnote 1]}
Aged 2 and 3 years on 31 August 2025 All eligible school aged children (reception year to year 11)	Offer LAIV If LAIV is contraindicated (or it is otherwise unsuitable) offer IIVc ^{[footnote 1]}

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Influenza vaccination programme 2025 to 2026

Background

2025 to 2026 flu programme summary

Main documentation

Influenza

Influenza vaccination programme

Legal frameworks to supply and/or administer influenza vaccines

Patient Group Direction

National protocol

Written instruction

Vaccine eligibility

Summary of eligible groups

Patients not in a risk group for whom their clinician believes influenza vaccine would be beneficial

Patients previously eligible for influenza vaccine but who are no longer in a risk group

Timing of vaccination

Pregnancy and breastfeeding

Vaccination of women who become pregnant late in the flu season

Administering influenza vaccine at the same time as whooping cough (pertussis) containing vaccine, respiratory syncytial virus (RSV) vaccine and/or anti-D immunoglobulin

Administering influenza vaccine to breastfeeding women

Influenza vaccine and its components

Vaccine antigens

Egg allergy and ovalbumin content of influenza vaccines

Vaccine adjuvant in aIIV

Latex

Antibiotics

Recommendations for the use of inactivated influenza vaccine

Table 1. Recommendations for the use of inactivated influenza vaccines

Adults 65 years of age and over and those who will become 65 before 31 March 2026

Adults in clinical risk groups aged under 65 years and pregnant women

Health and social care workers aged 65 years old and over

Individuals working with animals at risk of zoonotic influenza

Children in clinical risk groups for whom live flu vaccine (LAIV) is contraindicated

Children whose parents decline LAIV

Inactivated vaccines available during 2025 to 2026

Changes to the inactivated influenza vaccines for the 2025 to 2026 flu vaccination season

Inactivated influenza vaccines

Adjuvanted inactivated influenza vaccines (aIIV)

Cell-cultured inactivated influenza vaccine (IIVc)

High dose inactivated influenza vaccine (IIV-HD)

Recombinant inactivated influenza vaccine (IIVr)

Egg-cultured inactivated influenza vaccine (IIVe)

Live attenuated influenza vaccine (LAIV)

Recommendations for the use of LAIV

Table 2. Recommended vaccines for children

Live attenuated influenza vaccine (LAIV)

Presentation of LAIV

LAIV applicator components

LAIV efficacy

Cold adapted influenza virus

Transmission of vaccine virus in LAIV

Exposure to vaccine virus during administration

Shedding of vaccine virus

Number of influenza vaccine doses required (inactivated and LAIV vaccines)

Age 0 to 6 months

Age 6 months to 2 years and not in a clinical risk group

Age 6 months to 2 years and is in a clinical risk group or is a household contact of an immunocompromised person

Age 2 years to less than 9 years in a clinical risk group or is a household contact of an immunosuppressed individual

Age 2 years to less than 9 years and not in a clinical risk group

Age 9 years to less than 18 years

18 years and over (including pregnant women of any age)

Contraindications and precautions

Inactivated influenza vaccine and LAIV

Additional contraindications for LAIV

Risk of anaphylaxis following administration of inactivated influenza vaccine or LAIV

Acute exacerbation of asthma symptoms

Temporary deferral of immunisation

Vaccine ordering and national supply of additional adult vaccine

Ordering controls and excess stock

Vaccine storage

Storage of inactivated influenza vaccine

Storing LAIV

Shelf life of LAIV

Expired doses of any influenza vaccine

Vaccine storage incidents

Influenza vaccine preparation

Preparation of inactivated influenza vaccines

Preparation of LAIV

Vaccine administration