FOI release

Freedom of Information request about Astra Zeneca Covid Vaccine - Basis of dosing recommendations (FOI-21-041)

Published 24 March 2021

Thank you for your email.

The authorisation of 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.

The approval for use of the 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 Oxford/AstraZeneca COVID-19 vaccines, further information (including information for healthcare practitioners and recipients of the vaccine, and Public Assessment Reports for each vaccine) are available on the MHRA website. Links to these are provided below:

https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca

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.cas.mhra.gov.uk/ViewandAcknowledgment/ViewAttachment.aspx?Attachment_id=103741

If you have a query about the information provided, please reply to this email.

If you are dissatisfied with the handling of your request, you have the right to ask for an internal review. Internal review requests should be submitted within two months of the date you receive this response and addressed to: info@mhra.gov.uk

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Please remember to quote the reference number above in any future communications.

If you were to remain dissatisfied with the outcome of the internal review, you would have the right to apply directly to the Information Commissioner for a decision. Please bear in mind that the Information Commissioner will not normally review our handling of your request unless you have first contacted us to conduct an internal review. The Information Commissioner can be contacted at:

Information Commissioner’s Office

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Cheshire

SK9 5AF

Yours sincerely

MHRA Customer Service Centre

Medicines and Healthcare products Regulatory Agency

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