When alarm about potential side effects of AstraZeneca's COVID-19 shot halted vaccinations around Europe this month, many people worried it would damage public trust in the vaccine. Now legal action in Italy has added to the turbulence.

On March 11, a prosecutor in the Sicilian city of Syracuse placed two doctors and a nurse under investigation for possible manslaughter, following the sudden death of a navy officer just hours after he had received the shot made by AstraZeneca PLC.

Prosecutor Gaetano Bono also ordered the nationwide seizure of tens of thousands of doses of the same batch of vaccine. He told Reuters it was a precautionary measure — but his move angered health practitioners, who said they saw no need for it.