The European Medicines Agency (EMA) on Thursday concluded the AstraZeneca COVID-19 vaccine is "safe and effective" and is not linked to an increased risk in blood clots.

EMA chief Emer Cooke said the committee ruled "this is a safe and effective vaccine" and the benefits of the shot outweighed any possible risks. The vaccine, she added, was not associated with an increase in the overall risk of thromboembolic events or blood clots.

"We still cannot rule out definitely a link between these (blood clot) cases and the vaccine," Cooke, however, noted based on available evidence.

At least 20 European countries have fully or partially suspended the use of the AstraZeneca coronavirus vaccine following reports of suspected deaths from blood clots after vaccination, which prompted the EMA investigation.

As the world is struggling to contain the pandemic, with a third wave starting in many EU countries, vaccination is underway in an increasing number of countries with the already-authorized coronavirus vaccines.

Cooke said the EMA was looking to do observational studies to investigate further with European experts having been gathered for a review which, she added, was the EMA's highest priority. She further appealed to people who incurred any side effects to report them.

Dr. Sabine Strauss, chair of the EMA vaccine safety committee, echoed Cooke's comments on the benefits of the vaccine saying it had found "no evidence of a quality or a batch issue".

Strauss said individual cases from across Europe of thromboembolic events were looked into and that there was no higher overall risk of such things happening after being vaccinated.

Cooke also said the EMA was looking to raise awareness among people who have been vaccinated and are being vaccinated, about things they should watch out for, just in case they have any problem.

"If it was me, I'd be vaccinated tomorrow, but I would want to know that if anything happened to me after, what to do about it, and that's what we're saying today," Cooke said.

(With input from agencies)