[HN Gopher] T cells recognize recent SARS-CoV-2 variants ___________________________________________________________________ T cells recognize recent SARS-CoV-2 variants Author : onetimemanytime Score : 46 points Date : 2021-03-31 20:05 UTC (2 hours ago) (HTM) web link (www.nih.gov) (TXT) w3m dump (www.nih.gov) | burlesona wrote: | Sounds like good news. | | There's also this bit at the end: | | > Optimal immunity to SARS-Cov-2 likely requires strong | multivalent T-cell responses in addition to neutralizing | antibodies and other responses to protect against current SARS- | CoV-2 strains and emerging variants, the authors indicate. They | stress the importance of monitoring the breadth, magnitude and | durability of the anti-SARS-CoV-2 T-cell responses in recovered | and vaccinated individuals as part of any assessment to determine | if booster vaccinations are needed. | | I haven't heard a lot of discussion around that, but it seems | pretty logical to me that we'll continue to see substantial | numbers of new variants for this virus, and thus there's a good | chance we'll eventually need booster vaccinations to maintain | immunity, unless (until?) we could get the whole planet | vaccinated and eradicate the disease. | | But since eradication seems highly unlikely, I'm hoping that | we'll find the basic vaccines we've come up with so far can be | modified to target new variants much in the way we come up with a | new flu shot every year and don't have to go through the same | full approval and manufacturing ramp-up process. | Trasmatta wrote: | > But since eradication seems highly unlikely, I'm hoping that | we'll find the basic vaccines we've come up with so far can be | modified to target new variants | | My understanding is that one of the major benefits of mRNA | vaccines is how easy they are to both design and produce | (although storage and transportation is a challenge). It seems | likely we might need yearly boosters, and I think the mRNA | vaccines will be up to the task. | AbortedLaunch wrote: | An important, as of yet unresolved question, is whether those | changed vaccines will lead to the generation of new | antibodies vs. a boost of the existing ones, a phenomenon | called original antigenic sin. Fingers crossed... | yowlingcat wrote: | This is my biggest worry. I can't help but wonder (with a | very uneducated and uninformed opinion here) if we are | stoking or entering the next stage of an arms race. | tialaramex wrote: | Eradication would have been the economically most sensible | approach, but that was also true for elimination within the | countries that would be paying for it - and it's not what they | chose. Some of them apparently figured if you kill half a | million of your people and "open up" your economy you can... | offset the enormous cost of losing all those people by | pretending they aren't dead? I honestly don't know, I suspect | it'll turn out that nobody actually did any analysis, they just | assumed if they can spout a talking point and have the numbers | to push through the policy Mother Nature will have to go along | with them, and er, nope. | | So I don't expect them to pursue eradication either once the | immediate local threat from the pandemic recedes. There's no | great commitment to eradication generally from these countries, | the funding mostly comes from charitable donation, even though | obviously disease eradication makes economic sense as an | investment. How much money for example, did your government | spend on global elimination efforts for Rinderpest? Or did it | just say "Not our problem" the moment there was no disease in | their own cattle? | jsight wrote: | I'm not seeing any evidence that eradication of a virus like | this would have been at all likely, even with extreme | measures. | tialaramex wrote: | If the virus has a viable non-human reservoir then | eradication becomes very difficult and in some cases | impossible. We likely cannot get rid of Influenza because | viruses from that family thrive in a huge number of other | mammals. So you'd be chasing it down in pigs, and in | chickens, and it becomes an insurmountable challenge. | | But although this virus presumably originated in another | mammal species (it is assumed to have once been a bat | virus) it's not clear to me whether there's a real | reservoir in other species today, the vast bulk of the | world's infected seem to be humans. | | In a virus that lacks a viable animal reservoir you can | achieve eradication by "just" eliminating the virus in | humans in each place and ensuring infected humans don't | spread it into places where it was eliminated, a strategy | that costs money but is final. That's where the previous | SARS virus went - we eliminated it and it didn't come back, | and of course it's why Smallpox is gone. | | And eliminating SARS-CoV-2 is possible, because New Zealand | did it. They had outbreaks in elderly care a year ago, and | they locked down, tracked down every case, isolated every | infected person, and eliminated the virus. All subsequent | outbreaks have been connected to their border, if everybody | had done likewise the virus would be gone. Of course that | wasn't entirely realistic (other large islands like Great | Britain could definitely have at least attempted this but | they did not, but it's difficult to imagine North America | or Russia achieving elimination without a vaccine) but with | better tools now I think it could be attempted if the | political existed, which I argue it does not. | | The trickiest part about this virus for elimination from | 2022 onward is maybe it's viable as a virus that doesn't | cause much disease, especially in a vaccinated population. | If it's infecting otherwise healthy adults and just causing | sniffles for a week, once the pandemic headlines stop | nobody will isolate and prevent onward spread. In much of | the world (including the US) they'll even keep going to | work and give it to colleagues as well as those they live | with. Lots of coronaviruses thrive this way in humans. | rootusrootus wrote: | > much in the way we come up with a new flu shot every year | | I'm hoping that since it is a coronavirus, and not influenza, | it won't mutate anywhere near fast enough to evade vaccines on | a yearly basis. Right now SARS-CoV-2 is getting a best case | environment for mutation. When a substantial portion of the | world has been vaccinated, the mutation rate is going to drop | significantly, and hopefully with perhaps one more iteration of | the vaccine (given to the whole world, granted) we can dispense | with this virus altogether. | mmebane wrote: | Another recent study [1], discussed on This Week in Virology [2], | also found T-cell immunity to be robust against mutations. | However, there seems to be an open question of how well natural T | cells, trained on the whole virus, will compare to T cells | trained on vaccines that only have the spike protein or some | other subset. | | [1]: https://www.biorxiv.org/content/10.1101/2021.02.27.433180v1 | [2]: https://www.microbe.tv/twiv/twiv-736/ | jonny_eh wrote: | I recall reading that the enhanced immune response from the | vaccines were more protective than a natural infection. | dragontamer wrote: | Why is this post downvoted? | | I know that P.1 (Brazil variant) seems to totally avoid | natural immunity. The proof is from the city of Manaus, which | was over 75% infected in October 2020. A resurgent wave of | COVID19 hit in January 2021. | | At first, this didn't seem possible. But upon further study, | it seemed that P.1 was avoiding natural immunity. So its | reinfecting a ton of people in Manaus. | | ------------ | | In contrast, the Pfizer vaccine has shown to confer immunity | to both the original strain AND to P.1. As such, the immune | response created from Pfizer absolutely offers better | protection, once we account for the variants (especially P.1 | and B.1.351, which both have defenses against natural | immunity) | | B.1.351 is the other "immune avoiding" variant. And I await | for more studies before making a conclusion on that matter. | | -------- | | EDIT: It seems like the article is discussing B.1.351 among | its list of variants. That's good: the South African strain | seemed like it had some ability to avoid our immune system, | but our T-cells are still functioning against it. So a P.1 / | Manaus event probably won't happen. | timr wrote: | > I know that P.1 (Brazil variant) seems to totally avoid | natural immunity. | | This is completely false, and is a poor extrapolation from | a faulty initial data point. There have now been several | publications -- including the J&J clinical trial data | itself [1] -- which show that immune responses induced by | non-variant virus or vaccine are protective against the | Brazilian variant. | | > The proof is from the city of Manaus, which was over 75% | infected in October 2020. | | This number is based on a study that was published in | Nature in summer 2020, and used a number of questionable | "adjustments" to the raw seroprevalence data to arrive at | their conclusion. | | The parsimonious conclusion is that the paper citing 75% | seroprevalence in Manaus was wrong. | | [1] https://www.ucsf.edu/news/2021/03/420071/how-effective- | johns... | anonuser123456 wrote: | >The proof is from the city of Manaus, | | The Manaus data was not very compelling. Lots of selection | bias in their sampling. | dragontamer wrote: | There's multiple studies and multiple sets of data from | Manaus. You'll have to be more specific. Which data, from | which study, is untrustworthy? | anonuser123456 wrote: | I do not have the citation handy, but in one study, they | recruited individuals by enticing them with the results; | e.g. if you take take part in the study, we will give you | the antibody result. This would obviously bias the | results toward people that believed they had the virus, | but didn't have a test when sick. ___________________________________________________________________ (page generated 2021-03-31 23:01 UTC)