Global health experts came under increasing pressure on Tuesday to clear up questions over the safety of AstraZeneca’s Covid-19 shot, as Sweden, Latvia, Portugal, Luxembourg and Cyprus joined countries suspending their use in a further blow to Europe’s vaccination rollout.

The EU’s largest members — Germany, France and Italy — suspended use of AstraZeneca’s vaccine on Monday pending the outcome of investigations into unusual cases of a rare cerebral thrombosis in people who had received it.

The European Medicines Agency (EMA) 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 benefits continue to outweigh the risks, but this is a serious concern and it does need serious and detailed scientific evaluation,” Cooke told a news conference. A WHO committee of experts was reviewing the cases and was expected to issue a statement by the end of the day, a spokesman said.

The WHO and EMA had earlier joined AstraZeneca in saying there is no proven link, but some experts said the episodes of blood clots, bleeding and low platelet counts in younger people seemed to indicate a causal connection to the AstraZeneca shot.

Other epidemiologists note that similar cases have not been found in unusual numbers in Britain. More than 24 million people in Britain have so far received their first dose, with over 11 million having received the AstraZeneca shot.

Australia said it has no plans to halt the use of the AstraZeneca vaccine. The majority of Australia’s 25 million people will be administered the AstraZeneca vaccine. Thailand PM Prayuth Chan-ocha got a shot of AstraZeneca vaccine. “There are people who have concerns. But we must believe doctors, medical professionals,” he said. Reuters