An unusual type of blood clot among people who have received the AstraZeneca coronavirus vaccine is puzzling health officials in Europe. The UK now reports 30 cases, up from five, and no cases among people who received the Pfizer vaccine. There’s no evidence that the blood clots are connected to the AstraZeneca vaccine, the New York Times reports. That wouldn’t worry regulators enough to stop the vaccinations, anyway, because they occur so rarely—in Britain, one AstraZeneca recipient in 600,000 has had a blood clot. Still, drug agencies for the UK and European Union, whose regulator will meet next week, are investigating the issue. The unusual nature of the clots is that they’re often accompanied by a drop in blood platelets, which can bring heavy bleeding.
Some health officials in Europe are suspicious and tired of not knowing more, per the Times of Israel. “We have to stop speculating whether there is a link or not,” said the leader of a team reviewing cases in Oslo. “All of these cases had these symptoms three to 10 days after the AstraZeneca inoculation. We did not find any other triggering factor.” Norway’s drug regulator said a link is probable. Britain’s agency said Friday night that seven people have died of clots after receiving the AstraZeneca vaccine but nonetheless renewed its recommendation to take it. Four recipients in France have died, and the government now limits the vaccine’s use to people over 55, per the AP. The family of a 38-year-old woman who died after suffering brain clots filed a complaint Saturday demanding a manslaughter investigation. (Read more AstraZeneca stories.)