Coronavirus Live Updates: New Cases Are Increasing in U.S.

When the coronavirus arrived in Japan, people did what they normally do: They put on masks.

Face coverings are nothing new there. During flu and hay fever seasons, trains are crowded

with commuters half-hidden behind white surgical masks. Employees with colds, worried about the stigma of missing work, throw one on and soldier into the office.

Japan has reported more than 17,000 infections and just over 900 deaths, while the United States, with a population roughly two and a half times as large, has topped 1.9 million cases and is approaching 110,000 deaths.

“Japan, I think a lot of people agree, kind of did everything wrong, with poor social distancing, karaoke bars still open and public transit packed near the zone where the worst outbreaks were happening,” Jeremy Howard, a researcher at the University of San Francisco who has studied the use of masks, said of the country’s early response. “But the one thing that Japan did right was masks.”

During the pandemic, scientists have found a correlation between high levels of mask-wearing — whether as a matter of culture or policy — and success in containing the virus.

“I think there is definitely evidence coming out of Covid that Japan, as well as other countries which practice mask-wearing, tend to do much better in flattening the curve,” said Akiko Iwasaki, a professor of immunobiology at Yale.