Thread by @adamhamdy

1. Reinfection. Whisper it quietly lest you be dismissed as a crank or alarmist. What bothers me about the question of reinfection is that if you talk to a lot of leading epidemiologists, virologists and immunologists, they will say, "I expect to see reinfection."

2. Some will even say, "It will be like the endemics."

But in the main, they will only say it privately. Very few are prepared to share this hypothesis publicly. Whenever anyone talks about reinfection, they are accused of being irresponsible, but I believe the opposite is true.

3. Reinfection by endemic human coronaviruses is established science. This Columbia University study found median time to reinfection is 9 months, with short interval cases being seen 30 days after primary infection.

columbia.edu/~jls106/galant…

4. Prevailing evidence dictates it should be on those who hypothesise reinfection isn't possible to prove why they believe #SARS_CoV_2 will behave differently from the endemic coronaviruses.

5. "But MERS and SARS? Immunity to them lasts much longer."
Prove it.

"But look at the antibody response to SARS-CoV-2."
What's the duration? Neutralising titre? Proportion of off-target antibodies? Role of soluble ACE2 as a viral cloak?

6. Those who suggest reinfection are told to prove it, but reinfection is the default for endemic coronaviruses. The burden of proof should lie the other way. Or at least equally.

7. Why does it matter? Why can't we just carry on ignoring the risk? Well, a lot of scientists feel unable to speculate on this issue, such is the ire in some responses. Debate is being shut down, and we're being robbed of alternative viewpoints.

8. These viewpoints could be critical in informing policy. Governments are currently investing billions in vaccine and therapeutic approaches that assume a certain duration of protective immunity. By silencing those who might speak out about reinfection...

9. ...we are limiting the range of options that could enable us to tackle this virus. Yes, reinfection is scary. So is human to human transmission. So is Long Covid. So is multi-system infection. We've come to terms with many difficult concepts.

10. And it is only by coming to terms with them that we can properly address them. There are potential approaches that can tackle reinfection if it turns out to be happening, so as scary as it might seem, it's not cause for despair.

11. We won't change reality by shutting down debate. All we'll do is harm our ability to deal effectively with whatever reality we encounter. So the next time someone raises the issue of reinfection, maybe don't seek to shut them down.

12. Ask to see evidence, and engage in constructive debate. I don't think reinfection is proved, but it's also a long way from being disproved.