It is a small bright spot amid Covid-19, although the number of people saved from a flu death pales next to the number dying from the new pandemic. It also presents questions that doctors around the globe will likely be wrestling with for years: If flu can be nearly wiped out this season, why not every season? [...]

"In a normal year, there are 50 to 100 flu patients every day around this time of the year," said Sho Naito, who runs five clinics in the Tokyo metropolitan area. "But we recently have only two to three a week" at each site, he said.