FOI release

Freedom of Information request on adverse reactions to influenza vaccines (FOI 21-257)

Published 28 May 2021

Thank you for your email dated 2nd March 2021, where you requested data on all reactions reported via the Yellow Card scheme for influenza vaccines.

In your request, you mention that you would like to compare the data provided to that seen in the ADR summary published each week for COVID-19 vaccines; however, this comparison is not possible for a number of reasons. There are a range of factors that can lead to increased reporting of one vaccine over another, for instance, socio-demographic factors of vaccine recipients or whether or not they have been encouraged by information, or a healthcare professional, to make a report. No robust inferences can be drawn from such comparisons.

Overall, the number and nature of suspected adverse reactions reported so far is not unusual for an immunisation programme, and the data published and analysed by the MHRA tell us that the safety of the COVID-19 vaccines is as expected based on the robust clinical trial data that supported the authorisations.

The general safety profiles of the COVID-19 vaccines authorised in the UK are broadly similar to other types of routinely used vaccines. Our robust regulatory work continues to reinforce that the safety profile of the vaccines remains positive, and the benefits continue to far outweigh any known side effects.

Further to your request, please find enclosed Drug Analysis Prints (DAPs), which list all reported, suspected reactions associated with influenza vaccines up to and including 28/02/2021. Two DAPs are provided, one for the live attenuated influenza vaccines (LAIVs) and the second for inactivated flu vaccines. LAIVs are mostly given to children, and the inactivated flu vaccines 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. Underlying or concurrent illnesses may be responsible and such events can also be coincidental. • Additionally, 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.

As this data does not necessarily refer to proven side effects, you should refer to the product information (Summary of Product Characteristics (SPC) and Patient Information Leaflet (PIL)) for details on the possible side effects of each influenza vaccine, which can be found here.

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 this response’s date and can be addressed to this email address.

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