Scientists in South Korea have concluded that people cannot get coronavirus again after recovering from the disease, despite hundreds testing positive twice.
A total of 277 patients in the country - as well as in China and Japan - were believed to have fallen ill for a second time.
The new findings suggest that rather than indicating reinfection, the positive results were due to testing failures. Researchers at the South Korean centre for Disease Control and Prevention (KCDC) now said it is impossible for Covid-19 to reactivate in human bodies.
Positive test results on people who had recovered from the virus were due to "fragments" of the virus remain in in their bodies, but with no power to make them ill again or to infect others.