Fact Check-Reports made to Britain’s Yellow Card scheme are not confirmed adverse reactions to coronavirus vaccines

Reports made to the British government’s Yellow Card scheme for adverse drug reactions do not necessarily show side-effects of coronavirus vaccines, contrary to claims on social media.

This is a common misinterpretation of how the scheme works, and has been repeatedly covered by Reuters fact checks (here , here , here , here).

In this instance, a post on Facebook (here) has presented a table that appears to show the number of adverse reactions and deaths recorded under the Yellow Card scheme for the Oxford/AstraZeneca, Pfizer/BioNTech and Moderna COVID-19 vaccines.

Any health professional or member of the public can report suspected side effects from the vaccines through the Yellow Card scheme (

This data is then compiled into a weekly report (here) published by the Medicines and Healthcare products Regulatory Agency (MHRA).

According to the table in the Facebook post, the AstraZeneca shot caused a total of 717,250 reactions, including 864 fatalities, up until June 2, 2021.

For the Moderna vaccine, there were 9,243 reactions and 4 fatalities, while the Pfizer vaccine caused 193,768 reactions and 406 fatalities, the same post said.

Pointing to the Yellow Card scheme, the table is captioned: “Latest UK data you won’t see on the news, by the way these are facts extracted from the govs [government’s] own yellow card scheme!!”

However, even if these numbers were drawn from a previous MHRA report, they have been taken out of context.

This is because reports to the Yellow Card scheme are not confirmed adverse reactions, but suspicions that might well be coincidental.

“Many suspected ADRs [adverse reactions] reported on a Yellow Card do not have any relation to the vaccine or medicine and it is often coincidental that they both occurred around the same time”, the MHRA explains (here).

Due to the sheer scale of the vaccination program, it is accepted that some people will naturally experience a new illness after receiving the vaccine.

“It is therefore important that we carefully review these reports to distinguish possible side effects from illness that would have occurred irrespective of vaccination”, the MHRA says.


Missing context. Reports made to the Yellow Card scheme are not confirmed fatalities or adverse reactions to COVID-19 vaccines - but are suspicions that may be coincidental.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.