AstraZeneca COVID-19 vaccine linked to rare blood clots, EMA official says, but benefits still outweigh risks

A European Medicines Agency official drew a link Tuesday between AstraZeneca's COVID-19 vaccine and the rare reports of blood clots in vaccine recipients. But the shot's benefits still outweigh its risks, the official said as the agency itself wraps up its review of the clotting incidents. 

As the number of blood-clot reports rises, EMA vaccine chief Marco Cavaleri told the Italian newspaper il Messaggero it’s "clear that there is an association with the vaccine," as translated by Reuters. The benefits of the shot still outweigh the risks, he said.

The news comes ahead of an updated safety review from EMA—expected Wednesday or Thursday—and after the agency's March 18 decision to continue the shot rollout despite the small number of patients reporting serious, unexpected blood clots. Several countries had stopped using the vaccine ahead of that decision to wait for the EMA’s initial findings.

At the time, the agency said it couldn't rule out a link to the clots. EMA wanted to highlight the incidents so vaccine recipients could "spot and mitigate" any potential side effects, Executive Director Emer Cooke said.

Meanwhile, in the U.K., officials are considering restricting usage of the vaccine in people under 30, Channel 4 News reported on Monday. 

EMA experts have been reviewing the incidents since mid-March. The agency "has not yet reached a conclusion and the review is currently ongoing," the Amsterdam-based EMA said in a Tuesday statement to AFP.

"We will communicate and hold a press briefing as soon as the review is finalized. This is currently expected tomorrow (Wednesday, 7 April) or on Thursday, 8 April," it added.

More than 22 million doses of the vaccine have been administered so far, according to data from the European Center for Disease Prevention and Control.

RELATED: Europe endorses AstraZeneca's COVID-19 vaccine's safety amid blood clot concerns 

Throughout the process, AstraZeneca has said that patient safety is its “highest priority.”

"Regulators have clear and stringent efficacy and safety standards for the approval of any new medicine, and that includes COVID-19 Vaccine AstraZeneca," a spokeswoman said last month. "The safety of the vaccine has been extensively studied in Phase III clinical trials and peer-reviewed data confirms the vaccine has been generally well tolerated."

RELATED: AstraZeneca again cuts coronavirus vaccine delivery targets in Europe 

The safety concerns aren’t the only issue AstraZeneca is working through. Its European manufacturing operation has gotten off to a slower than expected start, leading the company to dramatically cut its dose delivery target for the first half of the year. In the U.S., the company has to look for another manufacturing partner after Emergent BioSolutions’ snafu in producing Johnson & Johnson’s shot.