Hong Kong: first 'proven' case of COVID reinfection

Researchers in Hong Kong Monday identified what they said was the first confirmed case worldwide of COVID-19 reinfection, raising questions about the durability of immunity, whether acquired naturally or with a vaccine.

"Our study proves that immunity for COVID infection is not lifelong -- in fact, reinfection can occur quite quickly," said Kelvin Kai-Wang To, a microbiologist at Hong Kong University's Faculty of Medicine and lead author of a forthcoming study that details the findings.

"COVID-19 patients should not assume after they recover that they won't get infected again," he told AFP in an interview.

Even people who have shaken off the virus should practice social distancing, wear masks and practise hand washing, he advised.

They should also get tested if suspect symptoms appear.

The case came to light when a 33-year old resident of Hong Kong passed through mandatory screening earlier this month at the Hong Kong airport on his way back from Europe. The so-called PCR swab test was positive.

This came as a surprise because the man had contracted -- and recovered from -- a COVID infection four-and-a-half months earlier, and was assumed to have immunity, especially after such...