Reports of people recovering from COVID-19 and then becoming sick again within months make the coronavirus seem like an almost unstoppable enemy—but virologists say fears may be overblown. Experts tell the New York Times that while it may be possible for people to become infected twice, they believe it would be very unlikely to happen within the space of a few months, or for the person to become much sicker the second time. They suspect that in at least some cases of reported reinfections, the person was wrongly declared virus-free after a test returned a false negative when the coronavirus was still lurking somewhere in their body. Columbia University virologist Angela Rasmussen tells the Washington Post that while experts hope immunity for recovered patients will last at least a year, it is too early in the pandemic to draw conclusion about how immunity develops or how long it persists.
Michael Mina, a Harvard immunologist, says while reports that antibodies decline sharply two or three months after infection have caused alarm, he says it is completely normal for antibody levels to go very, very, high then come down after an acute infection. Clinicians are "scratching their heads, saying 'What an extraordinarily odd virus that it’s not leading to robust immunity,’ but they’re totally wrong," Mina tells the Times. "It doesn’t get more textbook than this." He describes reports raising fears of widespread reinfection are "sensationalist clickbait." Experts also note that reinfections have been known to happen with many viruses, and with 15 million known coronavirus cases worldwide, reports of reinfection have been very rare. But "even rare occurrences might seem alarmingly frequent when a huge number of people have been infected," Rasmussen says. (Read more coronavirus stories.)