A man was reinfected with coronavirus – what does this mean for immunity?
There is still much that is unknown about Covid-19, but a few possible explanations can be given for what happened in this case
A 33-year old man was found to have a second SARS-CoV-2 infection about 4½ months after he was diagnosed with his first, from which he had recovered. The man, who showed no symptoms, was diagnosed when he returned to Hong Kong after a trip to Spain.
I am a virologist with expertise in coronaviruses and enteroviruses, and I’ve been curious about reinfections since the beginning of the pandemic. Because people infected with SARS-CoV-2 can often test positive for the virus for weeks and even months – probably because of the sensitivity of the test and due to leftover RNA fragments – the only way to really answer the question of reinfection is by sequencing the viral genome at the time of each infection and looking for differences in the genetic code...