NEW: Hong Kong has reported the first confirmed case of reinfection to the coronavirus. Details not on Twitter (there is a manuscript!) + what it means for immunity & herd immunity to the coronavirus: 1/x https://www.nytimes.com/2020/08/24/health/coronavirus-reinfection.html

So what does the reinfection case mean for immunity? Exactly what we expected, acc to @VirusesImmunity. The virus produces “non-sterilizing immunity,” meaning it doesn’t necessarily prevent reinfection—at least in some cases—but may produce milder disease 2nd time around 2/x

The person was infected 142 days apart, and with a European strain the second time apart. He had mild symptoms the first time and no antibodies. No symptoms the second time and some antibodies. 3/x

As @michaelmina_lab says, this is not unlike how you build memory to a face or a fact. The more exposures, the stronger and longer-lasting the memory — in this case the immune memory. Not at all surprising, in fact, he says. 4/x

But a reinfected person might still spread to others--*might* because not clear from this case. And that may mean that herd immunity will need a vaccine that does produce sterilizing immunity, the kind that destroys the virus on encounter and doesn’t allow for reinfection. 5/x

In other words, no big surprise here, keep calm and carry on. I saw the tweet at 7:30 am, so huge thanks to @VirusesImmunity @BrianRWasik @michaelmina_lab and Jeff Shaman, who responded to my urgent DMs and texts 6/x https://www.nytimes.com/2020/08/24/health/coronavirus-reinfection.html

Fun fact, in fact: I wrote the brief item at 7:35 am, right before recording @TheTakeaway with Jeff Shaman, and collared him for a call at the end of that. 7/7

Oh and also thanks to the researcher! Dr. Kelvin Kai-Wang To, who called me back promptly even though it was late HK time.