WHO finds no blood clot link to AstraZeneca vaccine

A review by the World Health Organization’s (WHO) vaccine safety group has found no increased risk of blood clotting conditions in people who received the AstraZeneca-Oxford vaccine.

The Global Advisory Committee on Vaccine Safety (GACVS) COVID-19 subcommittee met virtually on Tuesday and Friday to review available information on thromboembolic events (blood clots) and thrombocytopenia (low platelets) after administering the AstraZeneca vaccine, the WHO said in a statement on Saturday. The subcommittee reviewed clinical trial data and reports based on safety data from Europe, the UK, India and Vigibase, the WHO global database of individual case safety reports, it said.

Also read: Oxford’s COVID vaccine excellent, not linked to clotting cases: WHO

“The AstraZeneca COVID-19 vaccine (including Covishield) continues to have a positive benefit-risk profile, with tremendous potential to prevent infections and reduce deaths across the world,” the subcommittee reported.

“The available data do not suggest any overall increase in clotting conditions such as deep venous thrombosis or pulmonary embolism following administration of COVID-19 vaccines. Reported rates of thromboembolic events after COVID-19 vaccines are in line with the expected number of diagnoses of these conditions. Both conditions occur naturally and are not uncommon. They also occur as a result of COVID-19. The observed rates have been fewer than expected for such events,” it said.

The subcommittee said adequate education should be provided to health-care professionals and those being vaccinated to recognise the signs and symptoms of all serious adverse events after vaccinations with all COVID-19 vaccines, so that people may seek and receive prompt and relevant medical care and treatment.

Also read: India’s COVID task force studying Covishield amid side-effects concerns

So far, more than 2 crore doses of the AstraZeneca vaccine have been administered in Europe and more than 2.7 crore doses of the Covishield vaccine (AstraZeneca vaccine by Serum Institute of India) have been administered in India.

Several European countries – France, Germany, Italy, Denmark and Iceland –  recently suspended administration of the vaccine following reports that it may be causing blood clots in very rare cases.

On Friday UK and EU regulators said after a “thorough and careful review” that there is no evidence the AstraZeneca vaccine causes blood clots. The UK’s Medicines and Healthcare Products Regulatory Agency and the EU’s European Medicines Agency said people can have confidence in the vaccine’s benefits and should get immunised, the BBC reported.