Tunku Varadarajan:

“That is when the attacks started,” Dr. Bhattacharya, 56, says in a Zoom interview from his office in Palo Alto, Calif. In April 2020 he and several colleagues published a study that confirmed his hypothesis. The prevalence of Covid antibodies in Santa Clara County, where Stanford is located, was 50 times the recorded infection rate. That, he says, “implied a lower infection mortality rate than public-health authorities were pushing at a time when they and the media thought it was a virtue to panic the population.” His university opened a “fact finding” investigation into him after BuzzFeed made baseless charges of conflict of interest. “This was the most anxiety-inducing event of my professional life,” he says.

Shaken but steadfast, Dr. Bhattacharya, who is an economist as well as a physician, continued to oppose lockdowns, on Oct. 4, 2020, with the Great Barrington Declaration, of which he was one of three principal co-authors. (The others were Sunetra Gupta, a theoretical epidemiologist at the University of Oxford, and Martin Kulldorff, a statistician who has since been fired from Harvard for refusing a Covid vaccine.) The declaration dissented from the Anglo-American scientific establishment and argued for focused, age-based protection from Covid instead of universal and indiscriminate lockdowns.

Dr. Bhattacharya’s life was “completely overturned” in the months leading up to, and just after, Great Barrington. “I couldn’t eat or sleep for months,” he says. Not a big man, he lost 30 pounds. He received death threats. “There were some very, very nasty attacks.” Once-friendly colleagues stopped talking to him: “They crossed the street to avoid me.”