WHO and EMA on AstraZeneca: Safe vaccine

Foto: KoSSev

Despite assurances coming from both national and international authorities on the safety of all vaccines licensed to immunize the population, in recent weeks, reports on the alleged side effects of the AstraZeneca vaccines have repeatedly claimed public attention.

Citizens are especially disturbed by reports on the alleged thrombophilia or even deaths after the administration of this vaccine, such news, however, falls in favour of the anti-vaxxers agenda.

In its latest announcement, the World Health Organization shared details of the review of the COVID-19 subcommittee of the WHO Global Advisory Committee on Vaccine Safety (GACVS), which met on 16th and 19th March to review available information and data on thromboembolic events (blood clots) and thrombocytopenia (low 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 review of the available information, the subcommittee came to the following conclusions and recommendations:

“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 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.”

The WHO stated that very rare and unique thromboembolic events in combination with thrombocytopenia, such as cerebral venous sinus thrombosis (CVST), have also been reported following vaccination with the AstraZeneca COVID-19 vaccine in Europe, adding however that “it is not certain that they have been caused by vaccination.”

The European Medicines Agency’s Pharmacovigilance and Risk Assessment Committee has 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.

The European Medicines Agency – EMA had similar findings. In a longer report, they also shared details of their reviews and meetings, revealing that the vaccine is not associated with an increase in the overall risk of blood clots and that the benefits of the vaccine continue to outweigh the risk of side effects.

The EMA, however, noted the vaccine “may be associated” with very rare cases of blood clots associated with thrombocytopenia, i.e. low levels of blood platelets (elements in the blood that help it to clot) with or without bleeding, including rare cases of clots in the vessels draining blood from the brain (CVST).

“These are rare cases – around 20 million people in the UK and EEA had received the vaccine as of March 16th and EMA had reviewed only 7 cases of blood clots in multiple blood vessels (disseminated intravascular coagulation, DIC) and 18 cases of CVST. A causal link with the vaccine is not proven, but is possible and deserves further analysis.”

So far, more than 20 million doses of the AstraZeneca vaccine have been administered in Europe, and more than 27 million doses of Covishield vaccine (AstraZeneca vaccine produced by the Vaccination Institute of India) have been administered in India.

Due to the negative campaign, the vaccine named was changed to Vaxzevria. Vaxzevria is intended for people aged 18 years and older. It is made up of another virus (of the adenovirus family) that has been modified to contain the gene for making a protein from SARS-CoV-2. Vaxzevria does not contain the virus itself and cannot cause COVID-19.

WHO recommendations

The WHO recommends that adequate education should be provided to health-care professionals and persons being vaccinated to recognize 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 recommends that countries continue to monitor the safety of all COVID-19 vaccines and promote the reporting of suspected adverse events, while also agreeing with the European Medicines Agency’s plans to further investigate and monitor for these events.

At the same time, it will continue to review the safety data of all COVID-19 vaccines and update any advice as necessary.

The WHO COVID-19 vaccine safety surveillance manual provides guidance to countries on the safety monitoring and adverse events data sharing for the new COVID-19 vaccines, and can be accessed here.



Preuzimanje i objavljivanje tekstova sa portala KoSSev nije dozvoljeno bez navođenja izvora. Hvala na poštovanju etike novinarske profesije.