Dates, events, facts

A risk of reinfection

People who have gotten the new coronavirus and recovered can get it again in the future, health authorities say — the body does not become immune after infection.
On Wednesday, Japanese authorities reported the first confirmed case of reinfection. A tour guide in Osaka first tested positive for the coronavirus in late January, then was discharged from the hospital three weeks ago after showing signs of recovery. But she returned to the hospital after developing a sore throat and chest pain and tested positive for the coronavirus once again.
Zhan Qingyuan, director of pneumonia prevention and treatment at the China-Japan Friendship Hospital, warned last month that this could  happen.
Reinfections among patients in China have been reported as well.
The coronavirus family includes the viruses that cause SARS, MERS, and the common cold. Most cause upper-respiratory infections.
When a virus enters a human body, it tries to attach to and take over host cells. In response, our immune systems produce antibodies: proteins that recognize and remove viruses.