Geneva: The WHO Global Advisory Committee on Vaccine Safety (GACVS) COVID-19 subcommittee on safety signals related to the AstraZeneca COVID-19 vaccine today concluded that 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.
The GACVS COVID-19 subcommittee had met virtually on 16 and 19 March 2021 to review available information and data on thromboembolic events (blood clots) and thrombocytopenia (low platelets) after vaccination with the AstraZeneca COVID-19 vaccine.
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It 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 and based on a “careful scientific review of the available information”, it concluded that the reported rates of thromboembolic events after COVID-19 vaccines were 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 further concluded that while very rare and unique thromboembolic events in combination with thrombocytopenia, such as cerebral venous sinus thrombosis (CVST), had also been reported following vaccination with the AstraZeneca COVID-19 vaccine in Europe, “it is not certain that they have been caused by vaccination”.
“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,” it averred.
The subcommittee also referred to the European Medicines Agency’s Pharmacovigilance and Risk Assessment Committee, which had reviewed 18 cases of CVST out of a total of more than 20 million vaccinations with the AstraZeneca COVID-19 vaccine in Europe. “A causal relationship between these rare events has not been established at this time,” it stated.
While stating that it will continue to review the safety data from all COVID-19 vaccines and update any advice as necessary,the GACVS COVID-19 subcommittee recommended that countries continue to monitor the safety of all COVID-19 vaccines and promote reporting of suspected adverse events.
So far, more than 20 million doses of the AstraZeneca vaccine have been administered in Europe and more than 27 million doses of the Covishield vaccine (AstraZeneca vaccine by Serum Institute of India) have been administered in India. The subcommittee mentioned that while as of 17 March 2021, more than 120 million cases of COVID-19 infections, with more than 2 million deaths, had been reported globally, “vaccination remains a critical tool to help prevent further illness and death and to control the pandemic”. It recommended that adequate education should be provided to health-care professionals and persons 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.
“The GACVS subcommittee also agrees with the European Medicines Agency’s plans to further investigate and monitor for these events,” it stated.
– global bihari bureau
