The World Health Organization (WHO) does not rule out re-infection with COVID-19.
According to Gadin.Net, RIA Novosti quoted WHO spokeswoman Margaret Harris as saying at a briefing today.
According to him, sometimes people's tests with negative results later show positive:
"It is unknown at this time whether these people will be re-infected with the coronavirus or whether the tests will be problematic. However, it should be noted that such incidents occur very rarely.