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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& #39;re thinking this should be an obscure, wonky, data-driven debate, I have one word for you: hydroxychloroquine.)
(If you& #39;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 ">https://on.natgeo.com/2DpoH6V&q... #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 ">https://on.natgeo.com/2DpoH6V&q... #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 ">https://bit.ly/2WjAqKt&q... #COVID19 #Covid_19 #COVID #coronavirus
"Very strange and very surprising," she said.
https://bit.ly/2WjAqKt ">https://bit.ly/2WjAqKt&q... #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& #39;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& #39;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 ">https://nym.ag/3agwbos&q... #COVID19 #COVID_19 #COVID #coronavirus
See this @NYMag article by @dwallacewells for an excellent explanation.
https://nym.ag/3agwbos ">https://nym.ag/3agwbos&q... #COVID19 #COVID_19 #COVID #coronavirus
7/ Cross immunity in a nutshell:
"You don& #39;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& #39;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& #39;s not necessarily "total" immunity to #COVID19.
Instead, per @dwallacewells, it might mean "a faster immune response, a shorter period of infection, and a & #39;massively& #39; reduced risk of severe illness." https://nym.ag/3agwbos ">https://nym.ag/3agwbos&q...
Instead, per @dwallacewells, it might mean "a faster immune response, a shorter period of infection, and a & #39;massively& #39; reduced risk of severe illness." https://nym.ag/3agwbos ">https://nym.ag/3agwbos&q...
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 ">https://on.natgeo.com/2DpoH6V&q...
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">https://twitter.com/JamesToda...
See, e.g., this thread by @JamesTodaroMD (via @SubCyberSouth): https://twitter.com/JamesTodaroMD/status/1292873236716433416">https://twitter.com/JamesToda...
12/ So, @JamesTodaroMD argues, #lockdown and #WearAMask ordinances don& #39;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">https://twitter.com/JamesToda...
13/ And then there& #39;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& #39;s take: https://twitter.com/JamesTodaroMD/status/1292873251853684742">https://twitter.com/JamesToda...
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 ">https://bit.ly/33TxNDs&q...
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& #39;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& #39;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& #39;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">https://twitter.com/trvrb/sta...
