FOI release

Freedom of Information request on adverse clotting events post COVID-19 Vaccine AstraZeneca (FOI 21/501)

Published 28 June 2021

28th May 2021 FOI 21/501

Dear

Thank you for your Freedom of Information (FOI) request regarding adverse clotting events post COVID-19 Vaccine AstraZeneca.

Under the FOI act, you have requested to be provided with the following:

Please state how many of the four cases that followed second doses resulted in fatality Please state how many second doses of the AstraZeneca vaccine have been administered in the same reporting period in order to give a case incidence for second dose blood clot risks

As you may be aware, the MHRA publish a weekly COVID-19 ADR summary alongside analysis prints for each vaccine, these can be found here. It currently pertains to data received up to 19 May 2021. This contains details regarding specific reports including thrombo-embolic events with concurrent low platelets.

Up to 19 May 2021, the MHRA had received Yellow Card reports of 332 cases of major thromboembolic events (blood clots) with concurrent thrombocytopenia (low platelet counts) in the UK following vaccination with COVID-19 Vaccine AstraZeneca. These events occurred in 180 women,151 men aged from 18 to 93 years and the overall case fatality rate was 17% with 58 deaths. Seventeen cases have been reported after a second dose. Cerebral venous sinus thrombosis was reported in 120 cases (average age 46 years) and 212 had other major thromboembolic events (average age 55 years) with concurrent thrombocytopenia. The estimated number of first doses of COVID-19 Vaccine AstraZeneca administered in the UK by 19 May was 24.2 million and the estimated number of second doses was 10.7 million.

The overall incidence after first or unknown doses was 13.0 per million doses. Considering the different numbers of patients vaccinated with COVID-19 Vaccine AstraZeneca in different age groups, the data shows that there is a higher reported incidence rate in the younger adult age groups compared to the older groups. MHRA advises that this evolving evidence should be taken into account when considering the use of the vaccine. There is now some evidence that the reported incidence rate is higher in females compared to men although this is not seen across all age groups and the difference remains small. The overall incidence after second doses was 1.6 per million doses. This should not be directly compared to the incidence rate reported after the first dose given that the majority of second doses to date have been in older people and there is more limited follow up time following second doses in order to identify cases. These reports have also been analysed by the Government’s independent advisory body, the COVID-19 Vaccines Benefit Risk Expert Working Group, which includes lay representatives and advice from leading haematologists.

On the basis of this ongoing review, the advice remains that the benefits of the vaccine outweigh the risks in the majority of people.

Direct comparison of the summary provided above and the analysis prints is not possible. This is because this summary includes reports of CVST or other thrombo-embolic events with concurrent thrombocytopenia. Yellow Card reports may contain more than one reported reaction and the analysis prints are listed by individual reactions rather than whole reports. Therefore, summing the reactions listed in the prints will not equate to the total cases included within this summary.

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