Should we be worried about coronavirus reinfection?

A man in Hong Kong was recently reinfected with the coronavirus—the first known such case, according to news reports. But experts say the news isn’t a surprise, and that it’s likely that cases of reinfection will be less severe than initial cases because people’s immune systems will kick in.

“We’ve expected some people to get reinfected,” Ashish Jha, K.T. Li Professor of Global Health at Harvard T.H. Chan School of Public Health and director of the Harvard Global Health Institute, told the Today Show’s Hoda Kotb on August 25, 2020. “The good news here is it looks like it happens pretty infrequently, and the person who was reinfected in Hong Kong at least seemed to have a mild case.” Jha said the report of reinfection “certainly is not a cause for alarm or concern.”

In an August 24, 2020 New York Times article, a number of experts said that prior exposure to the coronavirus is likely to mean that any subsequent infections will be less severe. Michael Mina, assistant professor of epidemiology and a faculty member in the School’s Center for Communicable Disease Dynamics, said that building immune memory is similar to boosting the memory of a person. An initial infection with the coronavirus is likely to produce some level of immunity, and the virus will elicit a stronger immune response with each exposure, he said. “It is often these second and third exposures that help to solidify the memory response for the long term,” Mina said.

Watch Ashish Jha on the Today Show: Coronavirus Reinfection Concerns: New Questions Surrounding Immunity After First Known Case Reported

Read the New York Times article: First Documented Coronavirus Reinfection Reported in Hong Kong