The European Union’s drugs regulator reiterated that the benefits of AstraZeneca Plc’s Covid vaccine outweigh the risks as it urgently reviews safety data following the suspension of shots by a growing number of countries.

The comments were the second from the European Medicines Agency in as many days, and come amid reports of blood clots in some people who received shots. Its intervention follows dramatic measures by several EU member states to halt the use of Astra’s vaccine, potentially throwing the region’s already slow inoculation campaign further off track. EMA executive director, Emer Cooke, said she was concerned that the government decisions could undermine public support for vaccines.

“We are worried that there may be an effect on the trust in the vaccines,” Cooke said at a hastily convened press conference before the EMA makes a more formal recommendation on Thursday. “Our job is to make sure that the products we authorize are safe and can be trusted by European citizens.”

EU health ministers are holding a video call on Tuesday, where they’re expected to discuss concerns over side effects. The EMA will comment again on Thursday after it’s evaluated the latest information. Cooke declined to list all the possible conclusions, mentioning an additional warning on the product or possibly more radical action, “if there is a problem that can’t be solved.”

But she also said that “a situation like this is not unexpected when you vaccinate millions of people,” and there’s “no indication that vaccination has caused these conditions.”

The health scare piles on the issues the EU is already facing related to vaccinations. It’s been involved in a blame game with Astra over production issues, and there’s tension with the U.K. and U.S. over accusations of hoarding. Even within the bloc itself, governments are unhappy with how shots are being shared.

On Tuesday, Austrian Chancellor Sebastian Kurz called for a “correction mechanism” of vaccine distribution in the EU to avoid political tensions. Speaking in Vienna alongside the prime ministers of the Czech Republic, Bulgaria and Slovenia, he declined to be drawn on how such a mechanism should work, except saying that the guiding principle should be that every member state has the same access to vaccine doses at the same time.

Kurz said the leaders were already in talks with European Commission President Ursula Von der Leyen about their proposal.

‘Serious Concern’

The EMA’s latest intervention comes a day after France, Germany and other countries reversed course on the vaccine, suspending its use after initially continuing injections. Worries initially arose in Austria and Denmark, which stopped using some AstraZeneca shots last week.

Germany’s Health Ministry said that seven out of 1.6 million people who received the Astra shot recently experienced clotting in the brain area. That’s higher than the 1 to 1.4 cases that would normally be expected in such a population sample over a similar stretch of time.

On Tuesday, the U.K. repeated its view that the AstraZeneca shot, which was developed with the University of Oxford, is “safe and effective.”

The EMA’s Cooke stressed the need to take the time to evaluate every reported case and come up with an assessment that is science-based.

“This is a serious concern,” she said, that requires “thorough analysis of all the cases that are reported and evaluate whether this is a coincidence or indeed a causal effect.”

What Bloomberg Intelligence says:

“The reports of blood clots are anecdotal and insufficient to draw conclusions. A rare cluster of cases in Germany suggests rising risk, but could be coincidental.”

-- Sam Fazeli, senior pharmaceuticals analyst

Covid-19 Vaccine Safety: Need to Separate Anecdote From Data

The EU has received 14 million doses from AstraZeneca so far, and was expected to get about 120 million in the next six months. Of the Astra doses delivered to the EU, almost 8 million haven’t been administered.

The European Commission has committed to immunizing 70% of adults by the end of September, but the latest precautions could push back efforts, particularly if they persist.

With infection numbers creeping up again in countries like Germany, the risk of further vaccine shortages will increase pressure on politicians who have been punished for a lackluster immunization program. German Chancellor Angela Merkel saw her party slump to its worst ever results in two state elections on Sunday.