Germany, France, Italy Suspend Use of AstraZeneca’s Covid-19 Vaccine

Health regulators in the U.K. and Europe, along with AstraZeneca and its vaccine development partners at the University of Oxford, say there is no known connection between severe clotting and the shot. AstraZeneca has said the number of cases of blood clotting among the roughly 17 million people in the European Union and U.K. who have received the shot is lower than for the general population.

Europe’s medicines regulator said last week it was looking into around 30 reported cases of severe clotting, out of around five million people who have received the shot in the bloc. Last week, the regulator, the European Medicines Agency, said the “vaccine’s benefits currently still outweigh risks” and has continued recommending its use. The agency said most side effects are mild or moderate. Clinical trials didn’t raise flags about blood clotting as a risk.

The temporary halt to the AstraZeneca shots is another major setback in a wider vaccine rollout in Europe hamstrung by supply shortages and other hurdles at the same time as the continent wrestles with rising Covid-19 cases. Europe’s vaccination rates are far lower than in the U.S. and the U.K., where Covid-19 cases have stabilized or are falling.

Delays in giving out the AstraZeneca vaccine threaten to exacerbate vaccination-drive woes and could put further pressure on governments trying to speed things up. AstraZeneca has become a particular target of European politicians who have accused it of not doing enough to provide the continent with more shots.

French President

Emmanuel Macron,

in announcing his country’s pause, said the EMA was expected to publish a recommendation regarding the vaccine on Tuesday. The agency didn’t immediately respond to a request for comment.

The series of pauses across Europe threatens to undermine the AstraZeneca vaccine’s credibility just three months into its rollout. The U.K. was the first country to adopt the shot for mass use, at the end of December.

The shot previously faced skepticism over clinical-trial results that suggested it wasn’t as effective as other vaccines hitting the market. Some of those perceptions have faded as the U.K. inoculated millions of people with the shot, generating real-world data that showed it to be strongly effective in preventing severe disease and death.

The U.K.’s relatively quick vaccination program—with some 11 million AstraZeneca shots playing a key role—hasn’t raised blood-clotting concerns. The British medicines regulator has said it maintains its confidence in the vaccine and its safety.

Last week, reports surfaced of a potential clotting issue, with one death and a case of severe illness, in Austria. That country suspended one batch of the vaccine but said it didn’t have evidence of a connection between the health incidents and the shot and kept using it otherwise.

On Thursday, Denmark, Norway and Iceland halted use of the vaccine altogether. Danish authorities said they would wait at least two weeks before administering it again. The EMA, which acts much like the Food and Drug Administration in regulating medicine across the European Union, has already said serious blood clots weren’t any more common among vaccinated people than among the general population. It has said it is investigating the reported cases of multiple thrombosis, or the formation of blood clots within blood vessels, and similar conditions.

Last week, AstraZeneca warned it would fall short of projected vaccine deliveries to Europe in coming months, by 100 million doses—almost two-thirds less than what the continent was expecting based on the company’s earlier pledges.

AstraZeneca Chief Executive

Pascal Soriot

has repeatedly pushed back against doubts about the shot’s effectiveness and criticism of its rollout. Last month, AstraZeneca said it would roughly double global vaccine production to 200 million doses a month by April.

In Germany, the Paul Ehrlich Institute, which regulates vaccine use, said it became concerned by an unspecified number of new cases showing thrombosis, blood-platelet deficiency and bleeding in people soon after vaccination with the AstraZeneca shot. In a statement on its website Monday, the institute said it recommended temporarily halting use of the vaccine until further study by the EMA after seeing what it called a “striking accumulation” of those symptoms.

The regulator recommended that people who “feel increasingly unwell” more than four days after receiving a vaccination should seek medical attention. It flagged severe, persistent headaches or “pinpoint bleeding” of the skin as symptoms of concern.

On Friday, a nonprofit global organization of specialists in blood-clotting disorders and research, the Chapel Hill, N.C.-based International Society on Thrombosis and Haemostasis, advised continued use of the AstraZeneca vaccine. The society said that based on available data, the benefits of vaccination outweigh the risks “even for patients with a history of blood clots or for those taking blood-thinning medications.”

Covid-19 itself is known to cause blood clots, a factor researchers say they are taking into account when considering the benefits versus potential risks of vaccination.

Write to Bojan Pancevski at bojan.pancevski@wsj.com and Jenny Strasburg at jenny.strasburg@wsj.com