FOI release

Freedom of Information request about COVID-19 vaccines in pregnancy (FOI-21-159)

Published 7 May 2021

8th March 2021

FOI 21/159

Dear

Thank you for your FOI request concerning the use of Covid-19 mRNA Vaccine during pregnancy and breastfeeding.

The current advice from Public Health England is that the vaccines are not routinely recommended for those who are pregnant because although the available data from non-clinical studies have not raised any safety concerns, the limited data in this population is insufficient to recommend their routine use. However the potential benefits of vaccination may be important for those who are at very high risk of catching the infection or those with clinical conditions that put them at high risk of suffering serious complications from COVID-19. In these cases, the vaccine may be given. This is reflected in Section 4.6 of the Information for Healthcare Professionals for each vaccine which can be found using the following links:
Pfizer-Biontech vaccine = https://www.gov.uk/government/publications/regulatory-approval-of-pfizer-biontech-vaccine-for-covid-19, Oxford-AZ vaccine = https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca,
Moderna vaccine = https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-moderna

It is unknown whether each vaccine is excreted in human milk and there are no data on the safety of COVID-19 vaccines in breastfeeding or on the breastfed infant from clinical trials, however COVID-19 vaccines are not thought to be a risk to the breastfeeding infant. So the current advice from Public Health England is that the vaccines can be administered to women who are breastfeeding.

Information on how the vaccines were authorised is included for your information at the end of this email.

Since the launch of the COVID-19 immunisation campaign we have been proactively monitoring the safety of all approved COVID-19 vaccines for near real-time safety monitoring at population level. Information on adverse events experienced by pregnant or breastfeeding women is included in our adverse reaction assessment report and vaccine analysis prints which are published on the MHRA website at: https://www.gov.uk/government/publications/coronavirus-covid-19-vaccine-adverse-reactions

As you can see from the analysis prints we have received a small number of reports of vaccine use in pregnancy. Broadly these report similar reactions to those reported for non-pregnant individuals. A small number of reports of first trimester miscarriage (spontaneous abortion) have been received. Miscarriage is estimated to occur in about 1 in 4 pregnancies in the UK (outside of the pandemic) and most occur in the first 12 weeks (first trimester) of pregnancy. Cases of miscarriage reported following vaccination have occurred in the presence or absence of other reactions and our assessment so far is that there is no pattern to suggest an elevated risk related to vaccination.

We have also received a small number of reports from women who have experienced adverse reactions whilst breastfeeding. Again these have reported similar reactions in the mother to those reported by the general population. Some of these reports have also reported mild and short duration effects in their breastfed child (unsettled, crying, diarrhoea).

Based on current experience, the expected benefits of both COVID-19 vaccines in preventing COVID-19 and its serious complications far outweigh any known side effects for most people. As with all vaccines and medicines, the safety of COVID-19 vaccines is being continuously monitored.

Yours sincerely, MHRA

Further information on the vaccine authorisation procedures The authorisation of the Pfizer/BioNTech and the Oxford/AstraZeneca vaccines was done through an expedited rolling review. A ‘rolling review’ can be used to complete the assessment of a promising medicine or vaccine during a public health emergency in the shortest time possible. This is done as the packages of data become available from ongoing studies on a staggered basis. The temporary authorisation under Regulation 174 permits the supply of identified vaccine batches, based on the safety, quality and efficacy data submitted to MHRA. These authorisations do not constitute a marketing authorisation.

All vaccines are tested through three phases of clinical trials to ensure they meet the gold standard. Phase 1 trials are with a small group of people to make sure there are no safety concerns and determines the appropriate dosage for the best immune response. Phase 2 trials are conducted on a larger group of people to check the vaccine works consistently and that the immune response is sufficient. Phase 3 trials test the vaccines on thousands of people for scientists to assess if the vaccine is producing immunity that will prevent disease. Usually, these phases are run in sequence, but in an effort to find a safe and effective Covid-19 vaccine as quickly as possible, once safety has been ascertained through Phase 1, Phases 2 and 3 are being run in parallel. Extensive checks and balances are required at every stage of the development of a vaccine, and this is no different for a Covid-19 vaccine. No stages in the vaccine development processes were bypassed.

Information on the study conducted using the Pfizer/BioNTech vaccine and its results are available in a peer-reviewed journal, the New England Journal of Medicine. A link to this is provided below: https://www.nejm.org/doi/full/10.1056/NEJMoa2034577?query=featured_home

The approval for use of the Pfizer/BioNTech and Oxford/AstraZeneca COVID-19 vaccines in the UK followed a rigorous scientific assessment of all the available evidence of quality, safety and effectiveness by the UK regulator, the Medicines and Healthcare products Regulatory Agency (MHRA). The MHRA expert scientists and clinicians reviewed data from the laboratory pre-clinical studies, clinical trials, manufacturing and quality controls, product sampling and testing of the final vaccine, and also considered the conditions for its safe supply and distribution. The decision was made with advice from the Commission on Human Medicines (CHM), the government’s independent expert scientific advisory body. Regarding the MHRA approval of the Pfizer/BioNTech and the Oxford/AstraZeneca COVID-19 vaccines, further information (including information for physicians and recipients of the vaccine, and Public Assessment Reports [PARs] for each vaccine) are available on the MHRA website. Links to these are provided below: https://www.gov.uk/government/publications/regulatory-approval-of-pfizer-biontech-vaccine-for-covid-19
https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca

Further to the above, the Moderna vaccine has also recently been authorised for use. Further information on this is provided below: https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-moderna

Throughout this global pandemic, we have always been guided by the latest scientific advice. Having studied evidence on both the Pfizer/BioNTech and Oxford/AstraZeneca vaccines, the Joint Committee on Vaccination and Immunisation (JCVI) has advised that we should prioritise giving as many people in at-risk groups their first dose, rather than providing two doses in as short a time as possible.

The four UK Chief Medical Officers agree with JCVI that at this stage of the pandemic prioritising the first doses of vaccine for as many people as possible on the priority list will protect the greatest number of at risk people overall in the shortest possible time and will have the greatest impact on reducing mortality, severe disease and hospitalisations and in protecting the NHS and equivalent health services.

This is because the evidence shows that one dose of either vaccine provides a high level of protection from Covid-19.

For both vaccines, data provided to MHRA demonstrate that whilst efficacy is optimised when a second dose is administered both offer considerable protection after a single dose, at least in the short term. For both vaccines the second dose completes the course and is likely to be important for longer term protection.

The NHS across the UK will prioritise giving the first dose of the vaccine to those in the most high-risk groups. Everyone will still receive their second dose and this will be within 12 weeks of their first. The second dose completes the course and is important for longer-term protection.

The JCVI’s independent advice is that this approach will maximise the benefits of both vaccines allowing the NHS to help the greatest number of people in the shortest possible time. It will ensure that more at-risk people are able to get meaningful protection from a vaccine in the coming weeks and months, reducing deaths and starting to ease pressure on our NHS.

The following Department of Health and Social Care (DHSC) webpage for the independent report ‘Optimising the COVID-19 vaccination programme for maximum short-term impact’ from the Joint Committee on Vaccination and Immunisation (JCVI) provides the rationale for the government’s implemented dosing strategy:
https://www.gov.uk/government/publications/prioritising-the-first-covid-19-vaccine-dose-jcvi-statement/optimising-the-covid-19-vaccination-programme-for-maximum-short-term-impact

Further, the scientific basis from the JCVI concerning the current evidence on efficacy after single doses of the Pfizer/BioNTech, Oxford/AstraZeneca and Moderna vaccines is available in the public domain and is provided below: https://www.gov.uk/government/publications/prioritising-the-first-covid-19-vaccine-dose-jcvi-statement