Stanford researchers study causes of and treatments for long COVID

Time heals many wounds. But not all of them. Three years ago, on March 11, 2020, the World Health Organization officially bestowed pandemic status on COVID-19. Now, much of the fear that accompanied that declaration has subsided. We’ve turned the page on the virus, some have said. Plenty of people still get COVID-19, and some people still get very sick from it. But fewer people are ending up in the hospital or dying at the hands of SARS-CoV-2, the virus that causes it. A variety of factors are responsible: herd immunity from vaccination or previous infections, new drugs, better medical techniques, more experienced health care workers, and a likely mellowing of lethality in now-dominant viral strains that have opted to trade in virulence for contagiousness. Around half of the people who get infected by SARS-CoV-2 are asymptomatic — they don’t even know they had it. But some infected people’s symptoms persist for months, or...