Europe’s biggest countries, including Germany and France, have suspended use of AstraZeneca PLC’s COVID-19 vaccine amid a growing health scare that’s creating yet another delay for the European Union’s inoculation campaign.

Governments across the continent halted the distribution of the shots following reports of serious blood clotting, even as the EU drug regulator reiterated its support for the vaccine.

The suspensions mark a U-turn for some countries that had previously said inoculations should continue while the issue was investigated. Italy, Spain and Portugal also suspended use of the shot.