Dr. O’Connor, who researches H.I.V. and other viruses, including the new coronavirus, said some recent research had shifted his thinking about the current pandemic.

“H.I.V. is also spread while people feel fine,” he wrote in an email, “and consistent, correct condom use is a barrier to sexual virus transmission that works.”…

“Kids are going to need to wear them to school when classes resume,” Dr. O’Connor said. “Adults are going to need to wear them to work. If you want to go to a basketball game, when we get to that point, face mask. They need to be as ubiquitous as Kleenex, as quickly as possible.”

And they should probably be fashionable as well, he said, with celebrities promoting them. He suggested LeBron James.