Can people who recover from a bout with the new coronavirus become infected again — and again?

The Japanese government reported this week that a woman in Osaka had tested positive for the coronavirus for a second time, weeks after recovering from the infection and being discharged from a hospital.

Combined with reports from China of similar cases, the case in Japan has raised some uncomfortable questions. Reinfections are common among people who have recovered from coronaviruses that cause the common cold.

But those pathogens are very different from the new coronavirus, and experts said it’s unlikely that these are cases of people getting infected a second time.

“I’m not saying that reinfection can’t occur, will never occur, but in that short time it’s unlikely,” said Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York.