Statement of the WHO Global Advisory Committee on Vaccine Safety (GACVS) COVID-19 subcommittee on safety indications related to the AstraZeneca COVID-19 vaccine

As of March 17, 2021, more than 120 million cases of COVID-19 disease were reported worldwide, with more than 2 million deaths. Vaccination remains an essential tool to prevent further illness and death and to control the pandemic.

To date, more than 20 million doses of the AstraZeneca vaccine have been given in Europe and more than 27 million doses of the Covishield vaccine (AstraZeneca vaccine by Serum Institute of India) have been given in India.

The GACVS COVID-19 subcommittee met almost 16 and 19 March 2021 to review available information and data on thromboembolic events (blood clots) and thrombocytopenia (lower platelets) after vaccination with the AstraZeneca COVID-19 vaccine.

The subcommittee reviewed clinical trial data and reports based on safety data from Europe, the United Kingdom, India, and Vigibase, the WHO global database of individual case safety reports.

Based on a careful scientific examination of the available information, the sub-committee reached the following conclusions and recommendations:

  • The AstraZeneca COVID-19 vaccine (including Covishield) has a positive risk-benefit profile, with unique ability to prevent disease and reduce deaths worldwide.
  • The available data do not suggest an overall increase in clotting conditions such as deep venous thrombosis or pulmonary embolism after administration of COVID-19 vaccines. Reporting rates of thromboembolic events after COVID-19 vaccinations are in line with the expected number of these conditions. Both situations occur naturally and are not uncommon. They also occur as a result of COVID-19. The rates observed have been lower than expected for such events.
  • Although thromboembolic events have been very rare and specific in association with thrombocytopenia, such as cerebral venous sinus thrombosis (CVST), also reported after vaccination with the AstraZeneca COVID-19 vaccine in Europe, the diagnosis is uncertain. it was a vaccine that was to blame. The European Pharmaceutical Agency’s Pharmaceutical and Risk Assessment Committee has reviewed 18 cases of CVST out of more than 20 million vaccines with the AstraZeneca COVID-19 vaccine in Europe. No causal relationship has been established between these rare events at this time (1).
  • Health care professionals and individuals receiving the vaccine should be given appropriate education to recognize the signs and symptoms of all adverse events after vaccination with all COVID-19 vaccines, so that people can prompt and relevant medical care and treatment.
  • The GACVS subcommittee recommends that countries continue to monitor the safety of all COVID-19 vaccines and encourage reporting of suspected adverse events.
  • The GACVS subcommittee also agrees with the European Medicines Agency’s plans to further investigate and investigate these events.

The GACVS COVID-19 subcommittee will continue to review the safety data from all COVID-19 vaccines and update any advice as necessary. The WHO COVID-19 vaccine safety monitoring manual provides guidance to countries on safety monitoring and adverse event data sharing for the new COVID-19 vaccines, which can be accessed here.