PHILADELPHIA (KYW Newsradio) — European regulators say there is a possible link between AstraZeneca's COVID-19 vaccine and a very rare blood clot condition, but officials emphasize the benefits of getting the vaccine outweigh the risks.
The European Medicines Agency says unusual blood clots for people with a low blood platelet count should be listed among "very rare side effects" for the AstraZeneca vaccine. But overall, the shots are still critical in the fight to end the pandemic.
"The risk of mortality from COVID is much greater than the risk of mortality from these side effects," said the head of the EMA, Emer Cooke.
The agency says the latest data shows a few hundred of these very rare blood clots out of 35 million people vaccinated. Officials say from what they’ve seen, most of the cases are in women under 60 years of age within two weeks of vaccination. But they say there’s not enough evidence to nail down specific risk factors or an exact cause.
The World Health Organization and numerous other health authorities have also repeatedly stated the AstraZeneca vaccine is safe and effective and the protection it offers against COVID-19 outweighs the small risks of blood clots.
The results of a WHO study on this matter are pending but may be released this week.
Marco Cavaleri, the EMA's head of health threats and vaccine strategy, confirmed the link ahead of the announcement in an interview with Italian newspaper Il Messaggero.
“It is becoming more and more difficult to affirm that there isn’t a cause-and-effect relationship between AstraZeneca vaccines and the very rare cases of blood clots associated with a low level of platelets,” Cavaleri was quoted saying.
This specific issue has been difficult for the British drugmaker to shake. In March, more than a dozen countries, including Germany, paused the distribution of the AstraZeneca vaccine over concerns about blood clots. After regulators reviewed the vaccine again and affirmed that it was safe and effective, many countries resumed their vaccination campaigns.
Oxford University, which partnered with the company to develop this vaccine, just paused a clinical trial involving kids and teens.
“Whilst there are no safety concerns in the pediatric clinical trial, we await additional information,” an Oxford spokesperson said in a statement.
The vaccine is being used in over 50 countries but not in the United States, where the drugmaker will be filing for emergency use authorization at some point.
In March, AstraZeneca said Phase 3 clinical trials in the U.S. showed the vaccine was 76% effective against symptomatic COVID-19 and 100% effective at preventing severe illness and hospitalization. The company initially reported 79% overall efficacy, but U.S. health officials said the drugmaker used outdated information, so it had to recalculate the data.
The company says U.S. trials showed no blood clot issues.