Four of Europe’s most populous countries have now suspended the use of AstraZeneca’s coronavirus vaccine after reports of blood clots in some recently inoculated patients — even as the World Health Organization said it was safe and urged countries to continue using it.

Shortly after Germany said it would halt distribution of the AstraZeneca shots Monday, France, Italy and Spain announced that they would do the same, all describing their moves as precautionary measures taken while they await an impending analysis from European regulators. The four countries join the Netherlands, Denmark, Norway, Ireland and a few other nations that have paused use of the vaccine pending additional data.

WHO officials are still recommending the vaccine, and they said Monday that the greatest threat facing countries is a lack of access to vaccines — not blood clot concerns. Canadian Prime Minister Justin Trudeau, whose health officials have approved the AstraZeneca shot, called it “safe and effective.” The company has said there is no evidence of a link between its vaccine and clotting.

Here are some significant developments: