EU regulator says AstraZeneca vaccine safe but can’t rule out link to blood clots

The top drug regulator for the European Union announced Thursday that AstraZeneca’s coronavirus vaccine is safe and effective to use, after over a dozen countries halted administering its use over concern of blood clots.

However, the European Medicines Agency (EMA) also said it could not rule out a link to the blood clots, and said it would add a warning to the product in order to draw attention to the possibility of such rare side effects.

Including the warning and conducting outreach to health professionals and the public “will help to spot and mitigate any possible side effects,” said Emer Cooke, the executive director of the agency. 

The EMA said the benefits of protecting people against COVID-19 with a vaccine far outweigh possible risks. 

More than a dozen countries in Europe have temporarily suspended use of the vaccine, including Germany, France, Italy, Spain, Ireland, Norway and Denmark. They have been waiting on the EMA’s recommendations on how to proceed.

“Our scientific position is that this vaccine is a safe and effective option to protect citizens against COVID-19,” Cooke said. “We made this review our highest priority.”

The EMA published its findings, noting that out of about 20 million people who received the vaccine, there were only seven cases of blood clots in multiple blood vessels and 18 cases of blood clots in the brain.

“A causal link with the vaccine is not proven, but is possible and deserves further analysis,” the agency said.

The EMA investigation was focused on a small number of brain clots that have been reported following vaccinations. Most of these occurred in people under 55 and the majority were women.

The World Health Organization earlier this week endorsed the safety of the shot, and the United Kingdom’s top medical regulator on Thursday gave a similar message, urging countries to continue offering the shot.

But even if countries resume vaccinations immediately, experts think some damage has already been done.

Not only could the pauses set back vaccination efforts across Europe, but they could have ripple effects across the world and undermine confidence in the vaccine.

Hundreds of millions of Europeans are facing the prospect of another strict lockdown as the continent struggles with a new wave of COVID-19 infections and a flawed vaccine rollout. The fallout from suspending AstraZeneca’s shots could slow it down even more.  

Tal Axelrod contributed to this story, which was updated at 1:54 p.m.