Vaccine link to blood clots
April 8, 2021 - Europe’s drug regulator has reported 222 cases of rare blood clotting among 34 million adults vaccinated with AstraZeneca’s Covid shot -- but says the benefits of the vaccine outweigh the risks.
On April 7, the European Medicines Agency (EMA) stated that 169 of the blood clots were located in the brain, and 53 were in the stomach. All cases had the rare combination of blood clots, bleeding and low levels of platelets. Most of the clotting was found in women aged under 60.
The thrombi located in the brain were a form of clotting known as cerebral venous sinus thrombosis (CVST). Johns Hopkins University School of Medicine estimates that typically one in every 200,000 people of all ages develop CVST in a given year.
The situation “clearly demonstrates one of the challenges posed by large-scale vaccination campaigns,” said Emer Cooke, the EMA’s executive director. “When millions of people receive these vaccines, very rare events can occur that were not identified during the clinical trials.”
The UK regulator said the overall incidence of cerebral clots was about 4 cases for every 1 million people who’d received the vaccine. The reported risk in Europe is 1 in 100,000, according to the EMA.
Following a review by the UK’s drug regulator, 79 people had developed CVST by the end of March. Out of those 79 cases, 19 people died, three of whom were below 30. Britain’s Joint Committee on Vaccination and Immunisation has recommended an alternative shot for people ages 18 to 29.
The EMA has identified 35 cases of brain blood clots in connection with Pfizer and BioNTech’s vaccine Comirnaty, out of some 54 million people vaccinated