Hong Kong scientists reported a case of Covid-19 reinfection

Scientists from the University of Hong Kong reported Monday the case of a 33-year-old man who became reinfected with Covid-19 four and a half months after his first bout.

Dr. Kelvin Kai-Wang To, the microbiologist who led the work, said genome sequencing shows the two strains of the virus are "clearly different", making it the world's first proven case of reinfection.

The paper has been accepted by the journal Clinical Infectious Diseases but not yet published, and some independent experts urged caution until full results are available.