Independent report

JCVI interim advice: potential COVID-19 booster vaccine programme winter 2021 to 2022

Published 30 June 2021

In the situation where social mixing and social contact return towards pre-pandemic norms, it is expected that winter 2021 to 2022 will be the first winter in the UK when SARS-CoV2 will co-circulate alongside other respiratory viruses, including seasonal influenza virus. Seasonal influenza and SARS-CoV-2 viruses have the potential to add substantially to the ‘winter pressures’ usually faced by the NHS, particularly if infection waves from both viruses coincide. The timing and magnitude of potential influenza and SARS-CoV2 infection waves for winter 2021 to 2022 are currently unknown.

In the view of the Joint Committee on Vaccination and Immunisation (JCVI), the primary objective of a 2021 COVID-19 booster programme is to reduce the occurrence of serious COVID-19 disease.

The following precautionary advice is interim and may be subject to substantial change before being finalised.

JCVI advises that any potential booster programme should begin in September 2021, in order to maximise protection in those who are most vulnerable to serious COVID-19 ahead of the winter months. Influenza vaccines are also delivered in autumn, and JCVI considers that, where possible, a synergistic approach to the delivery of COVID-19 and influenza vaccination could support delivery and maximise uptake of both vaccines.

Any potential COVID-19 booster programme should be offered in 2 stages:

Stage 1. The following persons should be offered a third dose COVID-19 booster vaccine and the annual influenza vaccine as soon as possible from September 2021:

  • adults aged 16 years and over who are immunosuppressed

  • those living in residential care homes for older adults

  • all adults aged 70 years or over

  • adults aged 16 years and over who are considered clinically extremely vulnerable

  • frontline health and social care workers

Stage 2. The following persons should be offered a third dose COVID-19 booster vaccine as soon as practicable after stage 1, with equal emphasis on deployment of the influenza vaccine where eligible:

  • all adults aged 50 years and over

  • adults aged 16 to 49 years who are in an influenza or COVID-19 at-risk group. (Refer to the Green Book for details of at-risk groups)

  • adult household contacts of immunosuppressed individuals

As most younger adults will only receive their second COVID-19 vaccine dose in late summer, the benefits of booster vaccination in this group will be considered at a later time when more information is available. The initial objective for winter 2021 to 2022 is for persons in booster stages 1 and 2 to receive their influenza and COVID-19 vaccines in good time.

Apart from the current UK approved COVID-19 vaccines, the UK has placed orders for a range of other COVID-19 vaccines, some of which may become available for use in a booster programme. JCVI will review the use of these vaccines once they have received UK regulatory approval. Vaccines designed specifically against variants of concern will not be available in time for booster revaccination this autumn. The use of variant vaccines will be considered by JCVI in due course.

Additional scientific data will become available over the next few months which will require further consideration by JCVI ahead of any final advice. These include:

  • further data on the safety and effectiveness of COVID-19 vaccines used in the UK and internationally

  • clinical trial and real-world effectiveness data on the durability of protection beyond 6 months

  • clinical trial data on immune responses following a third vaccination (booster revaccination)

  • clinical trial data on reactogenicity and immunogenicity following booster revaccination with the same or alternative COVID-19 vaccines

  • clinical trial data on other COVID-19 vaccines in development

  • the emergence of any new variants of concern in the UK or internationally

  • data on the duration of immunity following a primary course

  • a better understanding of the immune correlates of protection

  • data on the effects of on-going SARS-CoV2 circulation in the population and its potential to confer long-term public health benefits

These data will also inform the formulation of advice with regards to booster revaccination for the purpose of minimising the COVID-19 case infection rate and the chance of new variants emerging.


Durability of protection

COVID-19 vaccination programmes have been undertaken at pace since the start of 2021. There is good evidence that a full course of any COVID-19 vaccine used in the UK will provide good protection against severe disease for at least 6 months for the majority, and there is some evidence that longer lasting protection may be afforded [footnote 1][footnote 2][footnote 3][footnote 4].

Any rise in COVID-19 disease will place pressure on the NHS, and NHS pressures are most acute in the winter months. The committee has therefore agreed an interim precautionary position on booster revaccination to ensure the protection that has been built up in the population does not decline through the winter months, and/or that immunity is maximised to provide additional resilience against variants. As more time elapses, more data are anticipated on the duration of protection provided through vaccination. These data will be reviewed ahead of the development of final advice in September 2021.

COVID-19 and influenza programmes

As well as SARS-CoV2, other common winter respiratory viruses place pressure on the NHS, including influenza. The circulation of influenza was very limited in the UK in the 2020 to 2021 season due to the use of non-pharmaceutical interventions, including social distancing measures. As a result, a lower level of population immunity against influenza is expected.

Mathematical modelling indicates the 2021 to 2022 influenza season in the UK could be up to 50% larger than typically seen [footnote 5]. It is also possible that the 2021 to 2022 influenza season will begin earlier than usual. To mitigate the potential impact from influenza, JCVI has advised extension of the influenza vaccination programme to adults aged 50 years and over in winter 2021 to 2022.

It is paramount that as many eligible adults as possible take up the offer of influenza vaccination, with those at highest risk vaccinated as early as possible.

JCVI considers that a synergistic approach to the delivery of COVID-19 and influenza vaccination may support delivery and maximise uptake of both vaccines in the population. The priority for deployment teams should be the delivery of influenza and COVID-19 booster vaccines to individuals identified in stage 1 at the earliest possible time, progressing to COVID-19 booster revaccination of individuals identified in stage 2 without causing undue delay and without displacement of the timely delivery of annual influenza vaccinations. Within each of the stages, where practicable, those with the longest interval since the second dose of their primary course of vaccination should be called first.

Early evidence on the concomitant administration of COVID-19 and influenza vaccines used in the UK supports the delivery of both vaccines at the same time where appropriate [footnote 6].

Protection of severely immunosuppressed individuals

Adults who are severely immunosuppressed, such as those who have had solid organ transplants, may not respond as well to COVID-19 vaccines and are at much higher risk of severe disease [footnote 7]. JCVI advises that those adults who are severely immunosuppressed should be offered COVID-19 booster revaccination at the start of the booster programme.

Unless otherwise eligible, adult household contacts of immunosuppressed individuals should be offered booster revaccination alongside those in stage 2 with allowance for operational flexibility.

  1. AstraZeneca data on the durability of protection and immune responses following COVID-19 vaccination [unpublished]. 

  2. Pfizer-BioNTech data on the durability of protection and immune responses following COVID-19 vaccination [unpublished]. 

  3. Moderna data on the durability of protection and immune responses following COVID-19 vaccination [unpublished]. 

  4. Dan, Mateus, Kato, et al. Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection. Science. 2021 Feb 5; 371(6529). 

  5. Modelling on influenza activity in the 2021/22 season. University of Warwick [unpublished]. 

  6. National Immunisation Schedule Evaluation Consortium (NISEC) data [unpublished]. 

  7. Monin-Aldama, Laing, Muñoz-Ruiz et al. Interim results of the safety and immune-efficacy of 1 versus 2 doses of COVID-19 vaccine BNT162b2 for cancer patients in the context of the UK vaccine priority guidelines. MedRxiv.