The U.S. has recently taken a sharp turn toward “living with,” rather than trying to avoid, COVID-19. Masks are no longer advised indoors for Americans in most parts of the country, according to the U.S. Centers for Disease Control and Prevention (CDC), and many mask and vaccine requirements have been repealed even in the most COVID-cautious parts of the country. In a poll conducted in March by Axios-Ipsos, 66% of Americans said they thought COVID-19 poses little or no risk.

It’s hard to blame people for relaxing a bit. For most vaccinated and boosted people, a case of COVID-19 is overwhelmingly unlikely to result in severe disease. But some experts say that the risk of Long COVID—the name for symptoms that last months or even more than a year after a COVID…