I felt it may worthwhile writing a mini thread about #COVID19 immunity following infection to provide some context to the WHO 'immunity passport' statement and its rapid clarification/retraction.
(1/5) https://twitter.com/WHO/status/1254160937805926405
There is no uncontroversial evidence for reinfection by COVID-19 at this stage. We do not know yet for how long someone infected will be immunised against subsequent infection, though on average it should likely be for a year or possibly more.
Importantly, even if residual immunity is insufficient to protect from #COVID19 re-infection, it is still expected to be protective insofar a secondary infection should lead to far milder symptoms.
The confusion about immunity in the context of ‘immunity passports’ stems mostly from the observation that some patients do not seem to mount a strong antigenic response. As such, despite having been infected, they won't test positive when diagnosed with serological tests.
Whether patients who failed to mount a strong antigenic response upon #COVID19 infection are susceptible to re-infection remains unknown since immunity may still be conferred by other immunological pathways (T-cell immunity).
You can follow @BallouxFrancois.
Tip: mention @twtextapp on a Twitter thread with the keyword “unroll” to get a link to it.

Latest Threads Unrolled: