Dr. Ding is a member of a shrinking club of people who are pretty sure they have never been infected with SARS-CoV-2, the virus that causes Covid-19. Geneticists and immunologists are studying factors that might protect people from infection, and learning why some are predisposed to more severe Covid-19 disease.
For many, the explanation is likely that they have in fact been infected with the virus at some point without realizing it, said Susan Kline, professor of medicine at the University of Minnesota Medical School. About 40% of confirmed Covid-19 cases are asymptomatic, according to a meta-analysis published in December in the Journal of the American Medical Association.
More than two years into the pandemic, most people worldwide have likely been infected with the virus at least once, epidemiologists said. Some 58% of people in the U.S. had contracted Covid-19 through February, the Centers for Disease Control and Prevention has estimated. Since then, a persistent wave driven by offshoots of the infectious Omicron variant has kept daily known cases in the U.S. above 100,000 for weeks.
Yet some people haven’t gotten sick or tested positive.
Author(s): Julie Wernau
Publication Date: 25 Jul 2022
Publication Site: WSJ