A World Health Organization (WHO) vaccine safety panel said on Wednesday that it considers that the benefits of the AstraZeneca COVID-19 vaccine outweigh its risks and recommends that vaccinations continue.

The WHO listed AstraZeneca and Oxford University's vaccine for emergency use last month, widening access to the relatively inexpensive shot in the developing world.

More than a dozen European countries have suspended use of the vaccine this week amid concerns.

The European Medicines Agency (EMA) has said it was investigating reports of 30 cases of unusual blood disorders out of 5 million recipients of the AstraZeneca vaccine. In total, 45 million COVID shots have been delivered across the region.

The EU regulator will release its findings on Thursday but its head, Emer Cooke, said she saw no reason to change its recommendation of AstraZeneca - one of four vaccines that it has approved for use.

The WHO said its Global Advisory Committee on Vaccine Safety is carefully assessing the latest available safety data for the AstraZeneca vaccine.

"Once that review is completed, WHO will immediately communicate the findings to the public," WHO said in its statement a day after its experts held a closed-door meeting.

"At this time, WHO considers that the benefits of the AstraZeneca vaccine outweigh its risks and recommends that vaccinations continue," it added.

Kate O'Brien, director of WHO's Department of Immunization, Vaccines and Biologicals, said that its vaccine safety panel was assessing whether adverse events such as blood clots were actually related to vaccination.

"We should not over-interpret these specific numbers that come out of trials. They are highly effective vaccines, they are life-saving vaccines, they are safe vaccines and we should get on with deploying them," O'Brien told a news conference.

"So anybody who is offered vaccine should take whatever is being offered by the programme and ensure that the vaccines that are being produced, are used to their maximum benefit," she said.