Its been a dreadful blow to Europes self-confidence, Id say, on the international stage, said Johan Norberg, a Swedish-based historian who has written about the continents pandemic response. We always have that propensity to retreat to our own national politics. ”

Those political considerations rippled throughout the continent in recent days after someone in Austria who had been given that the AstraZeneca vaccine died after developing blood clots. An unremarkable event, it prompted that country in early March to cease with a batch of this vaccine. Other countries soon followed suit, raising an alarm about any new reports of blood clotting, infrequent as they could have been.

In recent days, Spain’s health minister, Carolina Darias, spoke to her counterparts across the continent, according to an official from the ministry, who asked not to be named because the discussions were private. There was a case of thrombosis detected in Spain last weekend, and some areas had ceased distributing a batch of AstraZeneca vaccines, amid safety concerns.

However, the chief motive was political.

France, too, appeared to bow to pressure to act in unison with its powerful neighbors. It was relying upon the AstraZeneca vaccine to catch up on vaccinations after its glacial beginning, and Olivier Vé ran, France’s health minister, had said only days ago said there was “no reason to suspend. ”

But after Germany made its intentions clear — and people — Mr. Macron had a choice between following suit or being an outlier. And so on Tuesday, Mr. Véran changed his tune. France, he told Parliament, needed to “listen to Europe, listen to all the European nations. ”

That was the type of thing Mr. Speranza, Italy’s health minister, expected might happen after he spoke with his counterpart in Germany, in a conversation recounted by an Italian officer with knowledge of it.

When Mr. Speranza brought the issue to Prime Minister Draghi, he noticed the unbearable public pressure Italy would face if it alone used a vaccine considered too dangerous for Europe.