But the agency said it could not rule out a link with two rare blood clotting diseases seen in 25 people who received the vaccine, and said warnings should be added to information about the vaccine. provided to doctors and patients. Nine of these people died.
The European Pharmacovigilance Risk Assessment Committee (PRAC) has been invited to review the safety of the AstraZeneca vaccine, after over 20 European countries – including Germany, France, Italy and Spain – interrupted vaccinations following reports of rare bleeding disorders.
EMA executive director Emer Cooke told a press briefing that the committee found a reduced overall incidence of blood clots, compared to the general population, in nearly 20 million people who have received the vaccine so far in the world.
“The committee came to a clear scientific conclusion,” she said. “It is a safe and effective vaccine.”
But PRAC chairperson Sabine Straus said experts were unable to rule out a link to 18 cases of a condition called cerebral venous sinus thrombosis (CVST), and 7 cases of disseminated intravascular coagulation (DIC), both associated with a reduction in the number of blood platelets. In CVST, clots can prevent blood from flowing from the brain, causing bleeding. DIC is a condition in which blood clots form in many small blood vessels throughout the body, which can lead to serious organ damage.
The EMA will continue to investigate these incidents and possible links to the vaccine. But Cooke stressed that the benefits of the AstraZeneca vaccine in protecting people against COVID-19, which currently kills thousands of Europeans every week, far outweigh the risks of clotting.
“So what the committee recommended is to educate the public,” she said.
Some experts had speculated that the coagulation incidents were linked to particular batches of the vaccine. But Straus said the EMA did not support this theory. “The PRAC found no evidence of a quality or batch problem,” she said.
The EMA’s continued support for the vaccine followed reports claiming the Biden administration will announce Friday that it is shipping 2.5 million doses of the AstraZeneca vaccine to Mexico and 1.5 million to Canada. These injections will come from existing national supplies awaiting FDA clearance, which could come as early as next month after the end of a major trial of the vaccine in the United States.
The movement follows a dose request from Mexico earlier this week. Biden had told reporters on Thursday that the United States was considering shipping excess vaccine doses overseas once the national vaccination was completed. Senior FDA official Peter Marks testified in Congress on Wednesday that his agency was concerned about exporting too many excess doses, just in case immunity to the vaccine proves short-lived and booster shots are needed to the American population.
Others have speculated whether AstraZeneca’s vaccine would create more problems in the United States, as anti-vaxxers grabbed hold of the problems when it was rolled out.
“Does he really have a niche to fill? Would it be reliable enough? Or is it going to be just another headache? John Moore, a virologist at Weill Cornell Medical College in New York City who works on vaccine development, told BuzzFeed News earlier this week.