FOI release

Freedom of Information request on the side effects reported from the flu vaccine in children (FOI 21/1049)

Published 27 April 2022

8th October 2021

FOI 21/1049

Dear

Thank you for your email dated 14th September, where you asked for information on the following:

• Data relating to serious side effects of the flu vaccine in children (to include ages 10 and 14), reported through the Yellow Card Scheme.

The MHRA continuously monitors the safety of vaccines through a variety of pharmacovigilance processes including the Yellow Card scheme. As part of our signal detection processes all adverse reaction reports received by the Yellow Card Scheme are individually assessed and cumulative information reviewed at regular intervals. Vaccines encompass a wide variety of products with different indications, different ingredients and different mechanisms of action and as such safety for each vaccine is considered individually rather than as a group. If appropriate, regulatory action would be taken if any serious risks were confirmed.

Further to your request I can confirm up to and including 21st September 2021 we have received 2905 UK spontaneous suspected Adverse Drug Reaction (ADR) reports associated with the Live Attenuated Influenza Vaccine (LAIV), which is the flu vaccine administered in children and adolescents from 24 months to less than 18 years of age. 545 of these were considered serious ADR reports.

The seriousness criteria for ADR reporting were determined by a working group of the Council for International Organizations of Medical Sciences (CIOMS) and are defined as 6 possible categories which are explained on the Yellow Card. MHRA asks reporters to select one of the following criteria by ticking the appropriate box on the Yellow Card: (1) patient died due to reaction (2) life threatening (3) resulted in hospitalisation or prolonged inpatient hospitalisation (4) congenital abnormality and (5) involved persistent or significant disability or incapacity or (6) if the reaction was deemed medically significant. In addition to this, the seriousness of reaction terms has also been defined by the MHRA in our medical dictionary. Therefore, an ADR report can be serious because the reporter considers the reaction to be serious or because the reaction term itself is considered serious in our medical dictionary.

Please find attached a Drug Analysis Print (DAP) which contains information on all the UK spontaneous suspected ADR reports associated with LAIV received up to and including 21/09/2021. Please note that the DAP contains all ADR reports and is not restricted by patient age. As it is possible for one report to contain multiple ADRs, the number of ADRs is greater than the number of individual cases. Please find attached a DAP guidance sheet which provides you with further information on how to interpret the print.

When considering the attached spontaneous 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 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 medicine, and may 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.

As the data does not necessarily refer to proven side effects, you should refer to the product information which can be found here: https://products.mhra.gov.uk/ for details on the possible side effects of this vaccine.

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