The lucky few to never get coronavirus could teach us more about it

Somehow, Green never tested positive.Scientists around the world are investigating how a dwindling number of people such as Green have managed to dodge the coronavirus for more than two years, even after the highly transmissible omicron variant drove a record-shattering surge in cases this winter.A majority of Americans have contracted the novel coronavirus since it began to spread in the United States in early 2020, according to the Centers for Disease Control and Prevention.Experts hope that studying people who have avoided infection may offer clues — perhaps hidden in their genes — that could prevent others from being infected or more effectively treat those who contract the virus.Covid deaths no longer overwhelmingly among the unvaccinated as toll on elderly grows“What we are looking for is potentially very rare genetic variants with a very big impact on the individual,” said András Spaan, a clinical microbiologist and fellow at the Rockefeller University in New York who is spearheading a search for genetic material responsible for coronavirus resistance.Spaan said the international study has already enrolled 700 participants and is screening more than 5,000 people who have come forward as potentially immune to coronavirus infection.One of the study participants is 49-year-old Bevin Strickland, a nurse anesthetist from High Point, N.C., who volunteered in a Queens hospital for six weeks beginning April 2020, just as that pocket of New York City became the epicenter of the pandemic.“By the second day, I didn’t even care about getting covid because the patients were just heartbreaking,” said Strickland, who often worked without a mask to better connect with confused patients.Most of the worst cases were seniors who had been living in nursing homes. So she sought out the scientific study looking at the genetic makeup of people like her who never contracted the coronavirus despite repeated exposures.“I really do feel hopeful that they’re going to see some kind of similarity, some kind of gene in our DNA,” Strickland said.Studying the genes and other biological traits of people who never catch the coronavirus could shed light on how the virus develops, or how it infects the human body and makes people sick, said Jennifer Nuzzo, a professor of epidemiology at the Brown University School of Public Health. Other possible explanations could be prior exposure to a related virus or simply being born with an immune system better suited to fighting SARS-CoV-2.But finding individuals who have truly never had a coronavirus infection — not just those who had an asymptomatic infection or less severe case of covid-19 and did not know they had contracted the virus — is tricky.“Those people should be exceedingly rare in the United States at this point,” said Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington and who helps develop models that estimate how far the virus has spread.IHME models suggest that the number of people who have had the coronavirus in the United States may be even higher than recent CDC estimates based on blood tests, Murray said. The accuracy of many antibody tests wanes over time, so they may not identify someone who had been infected months ago, he added.“It’s an elusive target,” Murray said.Once researchers find people who avoided coronavirus infection, the next challenge is determining how they did so.Because masks, vaccines and social distancing can significantly reduce transmission, those factors may eclipse any biological differences between people who have not been infected and those who have tested positive.Virus mutations aren’t slowing down. His tests were always negative.Many people who haven’t yet contracted the virus don’t fully understand how they have evaded infection — and some believe they will eventually get sick with covid.“It’s got to be a combination of caution, circumstance and luck,” said Bob Wachter, professor and chair of the department of medicine at the University of California at San Francisco, who has not had the coronavirus.People who always wear masks in indoor public spaces, stay up to date on vaccines and boosters, test frequently, and avoid high-risk gatherings or travel may have had fewer chances to catch the virus, Wachter said. “And I don’t want to give that to anyone.”Another rare virus puzzle: They got sick, got treated, got covid againExperts say another way to home in on people who have truly never had the coronavirus is to study individuals, such as health-care providers and professional athletes, who were consistently required to test throughout the pandemic.“If you’re a physician who has been practicing, there’s no way you weren’t exposed quite considerably,” said Murray, the global health researcher at the University of Washington.During the worst of the covid surges, James Park was seeing 12 to 18 covid patients a day at the University of Pennsylvania hospital in Philadelphia where he works as a doctor and associate professor of clinical medicine.