Coronavirus Reinfections Are Real but Very, Very Rare

Reports of reinfection with the coronavirus evoke a nightmarish future: Repeat bouts of illness, impotent vaccines, unrelenting lockdowns — a pandemic without an end.

A case study published Monday, about a 25-year-old man in Nevada, has stoked those fears anew. The man, who was not named, became sicker the second time that he was infected with the virus, a pattern the immune system is supposed to prevent.

But these cases make the news precisely because they are rare, experts said: More than 38 million people worldwide have been infected with the coronavirus, and as of Monday, fewer than five of those cases have been confirmed by scientists to be reinfections.

“That’s tiny — it’s like a microliter-sized drop in the bucket, compared to the number of cases that have happened all over the world,” said Angela Rasmussen, a virologist at Columbia University in New York.

In most cases, a second bout with the virus produced milder symptoms or none at all. But for at least three people, including one patient in Ecuador, the illness was more severe the second time around than during the first infection. An 89-year-old woman in the Netherlands died during her second illness.

Rare as these cases may be, they do indicate that reinfection is possible, said Akiko Iwasaki, an immunologist at Yale University, who wrote a commentary accompanying the Nevada case study, published in The Lancet Infectious Diseases.

“It’s important to note that there are people who do get reinfected, and in some of those cases you get worse disease,” Iwasaki said. “You still need to keep wearing masks and practice social distancing even if you have recovered once from this infection.” ...

In most cases, a second bout with the virus produced milder symptoms or none at all. But for at least three people, including one patient in Ecuador, the illness was more severe the second time around than during the first infection. An 89-year-old woman in the Netherlands died during her second illness.

Rare as these cases may be, they do indicate that reinfection is possible, said Akiko Iwasaki, an immunologist at Yale University, who wrote a commentary accompanying the Nevada case study, published in The Lancet Infectious Diseases.