FOI release

Freedom of Information request on adverse reactions to influenza vaccines (FOI 21-242)

Published 28 May 2021

8th April 2021 FOI 21/242 Dear

Thank you for your email dated 09 March 2021, where you requested a list of reported adverse effects from flu injections in 2019.

It may first be helpful if we provide you with some background information relating to the MHRA, the Yellow Card scheme and the work we carry out. The Medicines and Healthcare products Regulatory Agency (MHRA) is an executive Agency of the Department of Health that acts on behalf of the Ministers to protect and promote public health and patient safety by ensuring that medicines, healthcare products and medical equipment are used safely and meet appropriate standards of safety, quality, performance and effectiveness. The MHRA assesses the balance of risks and benefits of all medicines at the time of initial licensing and throughout their use in clinical practice. Where appropriate, the MHRA seeks advice from the independent Commission on Human Medicines (CHM). The reporting of adverse drug reactions (ADRs) by both healthcare professionals and members of the public through the Yellow Card scheme enables the continued monitoring of the benefit/risk balance for medicinal products following their market authorisation.

Please find enclosed a Drug Analysis Print (DAP) which lists all UK spontaneously reported reactions on our database associated with influenza vaccine injections from 01/01/2019 up to and including 31/12/2019. This DAP contains suspected ADRs reported following inactivated influenza vaccines, which are typically administered to adults, especially the elderly. Please refer to the attached information sheet for guidelines on how to interpret the DAP.

When considering the attached spontaneous ADR data, it is important to be aware of the following points:

• A reported reaction does not necessarily mean it has been caused by the vaccine, only that the reporter had a suspicion it may have. Each year, millions of doses of routine vaccinations are given in the UK alone, and when any vaccine is administered to large numbers of people, some recipients will inevitably experience illness following vaccination. The fact that symptoms occur after the use of a vaccine or medicine, and are reported via the Yellow Card Scheme, does not in itself mean that they are proven to have been caused by it. Underlying or concurrent illnesses may be responsible and such events can also be coincidental.

• It is also important to note that the number of reports received via the Yellow Card scheme does not directly equate to the number of people who suffer adverse reactions and therefore cannot be used to determine the incidence of a reaction or compare the safety profile of different vaccines. ADR reporting rates are influenced by the seriousness of ADRs, their ease of recognition, the extent of use of a particular vaccine, the number of doses administered, and the population being vaccinated. The number of reports may also be stimulated by promotion and publicity about a drug. Reporting tends to be highest for newly introduced medicines during the first one to two years on the market and then falls over time. The product information for all inactivated influenza vaccines can be found on the electronic Medicines Compendium (eMC) website via the link below: https://www.medicines.org.uk/emc/search?q=influenza&filters=activeingredients[141,2436,1459]&offset=1&limit=50&orderBy=product&refreshFilters=true

I hope the information provided is helpful, but 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 of this response; and can be addressed to this email address.

Yours sincerely, FOI Team, Vigilance and Risk Management of Medicines Division