The European Medicines Agency’s Safety Committee has concluded that the formation of unusual blood clots in combination with a low platelet count should be included in the list of very rare side effects of the AstraZeneca vaccine.
This is stated in the press release of the EU regulator, published on Wednesday.
At the same time, according to the regulator, the benefits of using the AstraZeneca vaccine continue to outweigh the risks.
In reaching this conclusion, the committee took into account all the evidence currently available, including the recommendations of the ad hoc expert group.
“The EMA reminds health professionals and people who receive the vaccine of the possibility of very rare cases of blood clots in combination with low platelet levels within two weeks of vaccination,” the EU regulator said in a statement.
The regulator noted that at the moment, the majority of reported cases of thrombosis occurred in women under the age of 60 years within two weeks after vaccination. However, based on the currently available data, specific risk factors have not been confirmed.
People who have received the vaccine are advised by the regulator to seek immediate medical attention if they develop symptoms of this combination of blood clots and low platelet levels.
The EMA Committee noted that blood clots in vaccinated patients formed in the veins of the brain (cerebral venous sinus thrombosis) and the abdominal cavity (internal vein thrombosis), and in the arteries, along with low platelet levels, sometimes with bleeding.
At the same time, the EMA notes that the combination of blood clots and low platelet counts is very rare, and the overall benefits of the vaccine in preventing COVID-19 outweigh the risks of side effects.
A likely explanation for the combination of blood clots and low platelet levels is an immune response, leading to a condition similar to that sometimes seen in patients treated with heparin, the regulator notes.
The EMA Committee has requested new studies and amendments to the current ones to provide more information and promises to take any further action necessary.
So far, the EMA has recommended the AstraZeneca vaccine as safe and pointed to the lack of evidence of a link between the vaccine and blood clots. However, several EU countries, including Germany, have restricted the use of the vaccine.
In early March, dozens of European countries suspended the use of the vaccine due to such reports, but after the conclusion of the EU regulator, they mostly resumed vaccinations.