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1/ The next hot-button issue in #COVID19 debates: the relative importance of #antibodies versus T cells in #COVID_19 immune response.
(If you're thinking this should be an obscure, wonky, data-driven debate, I have one word for you: hydroxychloroquine.)
(If you're thinking this should be an obscure, wonky, data-driven debate, I have one word for you: hydroxychloroquine.)
2/ Some background. Antibodies are not the only possible source of #COVID19 immunity.
Or as this interesting @NatGeo article puts it, "antibodies might not be telling the whole story when it comes to #Covid_19 immunity."
https://on.natgeo.com/2DpoH6V #COVID
Or as this interesting @NatGeo article puts it, "antibodies might not be telling the whole story when it comes to #Covid_19 immunity."
https://on.natgeo.com/2DpoH6V #COVID
3/ Dr. Soo Aleman of Sweden tested patients who previously tested positive for #COVID19, as well as their close contacts. She found that hospitalized patients had strong antibody and T cell responses to #COVID_19 -- no surprise there.
#COVID #coronavirus
#COVID #coronavirus
4/ "But two-thirds of the close contacts who were asymptomatic showed a subsequent T-cell response, even though tests didn’t detect any antibodies."
"Very strange and very surprising," she said.
https://bit.ly/2WjAqKt #COVID19 #Covid_19 #COVID #coronavirus
"Very strange and very surprising," she said.
https://bit.ly/2WjAqKt #COVID19 #Covid_19 #COVID #coronavirus
5/ (Note: of these asymptomatic close contacts of #COVID19 patients who had a T-cell response but no antibodies, we don't know if they never had antibodies or if they had antibodies that then declined to undetectable levels.)
#Covid_19 #COVID
#Covid_19 #COVID
6/ Then there's the issue of "cross-reactive" T-cell immune responses or T-cell "cross immunity."
See this @NYMag article by @dwallacewells for an excellent explanation.
https://nym.ag/3agwbos #COVID19 #COVID_19 #COVID #coronavirus
See this @NYMag article by @dwallacewells for an excellent explanation.
https://nym.ag/3agwbos #COVID19 #COVID_19 #COVID #coronavirus
7/ Cross immunity in a nutshell:
"You don't necessarily need to catch COVID-19 for your T-cells to know how to fight it, because previous exposure to similar coronaviruses (like the common cold) had already taught your immune systems how to respond."
"You don't necessarily need to catch COVID-19 for your T-cells to know how to fight it, because previous exposure to similar coronaviruses (like the common cold) had already taught your immune systems how to respond."
8/ A caveat on cross immunity: it's not necessarily "total" immunity to #COVID19.
Instead, per @dwallacewells, it might mean "a faster immune response, a shorter period of infection, and a 'massively' reduced risk of severe illness." https://nym.ag/3agwbos
Instead, per @dwallacewells, it might mean "a faster immune response, a shorter period of infection, and a 'massively' reduced risk of severe illness." https://nym.ag/3agwbos
9/ So why does the relative importance of antibodies versus T cells in #COVID19 immunity matter?
It could have implications for the efficacy of a vaccine, societal responses to #COVID, and the necessity/wisdom of #lockdown.
#coronavirus #COVID_19
It could have implications for the efficacy of a vaccine, societal responses to #COVID, and the necessity/wisdom of #lockdown.
#coronavirus #COVID_19
10/ On a #COVID19 vaccine, reports of no antibodies but widespread T-cell response "raise concerns about a vaccine, since stimulating antibody production is a key strategy by which immunizations protect against disease." https://on.natgeo.com/2DpoH6V
11/ On societal response/ #lockdown, some argue that T-cell immunity, including cross immunity, means that we can reach effective herd immunity at a much lower threshold.
See, e.g., this thread by @JamesTodaroMD (via @SubCyberSouth): https://twitter.com/JamesTodaroMD/status/1292873236716433416
See, e.g., this thread by @JamesTodaroMD (via @SubCyberSouth): https://twitter.com/JamesTodaroMD/status/1292873236716433416
12/ So, @JamesTodaroMD argues, #lockdown and #WearAMask ordinances don't really deserve the credit for the current success in controlling #COVID19 now enjoyed by some of the hardest-hit places (e.g., my home city of New York). https://twitter.com/JamesTodaroMD/status/1292873250813468674
13/ And then there's the case of Sweden, which everyone loves to argue over when it comes to #COVID19 and #lockdown (or the lack thereof). Here is Dr. Todaro's take: https://twitter.com/JamesTodaroMD/status/1292873251853684742
14/ Speaking of Sweden, Swedish doctor Sebastian Rushworth argues that T cells are much more important than antibodies for #COVID19 immunity -- but we test for #antibodies "because it is easy and cheap" (also via @SubCyberSouth): https://bit.ly/33TxNDs
15/ Dr. Rushworth further argues that the reason Sweden is doing so well today is because it "ripped the metaphorical band-aid off quickly and got the epidemic over and done with in a short amount of time" (because of widespread T cell immunity).
16/ Speaking for myself, I don't have a strong view one way or the other on the relative importance of antibodies versus T cells when it comes to #COVID19 immunity; I'm still reading and educating myself.
#COVID_19 #COVID #coronavirus
#COVID_19 #COVID #coronavirus
17/ But I do predict that what should be a scientific, scholarly, data-driven debate about antibody versus T-cell immunity is about to become very, very politicized.
#COVID19 #COVID_19 #COVID #coronavirus #antibody #antibodies #lockdown #vaccine #vaccines
#COVID19 #COVID_19 #COVID #coronavirus #antibody #antibodies #lockdown #vaccine #vaccines
18/ Here's another interesting thread, by @trvrb (via @kaustuvs). He argues that both population immunity AND societal responses like social distancing and mask wearing are contributing to reduced #COVID19 spread. https://twitter.com/trvrb/status/1291860659118804992
