ROME — Giulio Macciò tested negative for the coronavirus and spent weeks receiving treatment for emphysema in a sealed-off hospital under the care of doctors and lung specialists — and a nurse who had refused to be vaccinated. On March 11, he unexpectedly died. A post-mortem swab found that he had contracted the virus, as had 14 other patients and the unvaccinated nurse who spent her shifts in his midst.

“It makes no sense that a person whose job is to heal the sick gives them Covid and kills them,” said Mr. Macciò’s son, Massimiliano Macciò, who filed a complaint against the San Martino hospital in the northern Italian city of Genoa. He believes that the nurse, one of an estimated 400 who have refused vaccination against Covid-19 at the hospital, infected his father, who died unvaccinated at 79.

As vaccination rollouts build momentum, businesses everywhere are grappling with whether they can require the inoculation of their employees, raising thorny ethical, constitutional and privacy issues around Europe and the United States. But that quandary becomes all the more urgent when the person is your health care worker.

In Italy, the original Western front in the war against Covid, a rash of outbreaks in hospitals where medical workers have chosen not to be inoculated has raised fears that their stance is endangering public health. It has also prompted a forceful response from an Italian government that is struggling to get vaccinations on track.