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Vaccines should end the pandemic, despite the variants, say experts

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Re: Vaccines should end the pandemic, despite the variants, say experts

#41

Post by Trasmatta »

monoideism wrote: post #37
Trasmatta wrote: post #25

Earlier quoted context omitted.

It's crazy to think about how HIV has killed some ~32 million people, and yet we rarely hear about it anymore. COVID probably won't even hit 4 million deaths (barring some much deadlier variant that we can't easily produce a new vaccine for).

Yeah, but that's > 3 million over 12 months vs 32 million over 40 years, the majority before 2010. AIDS was a huge deal back when there was no treatment for it.

Right, I don't mean to downplay the severity of COVID at all. It's just interesting that we generally don't hear a lot about HIV/AIDS anymore, even though there were still 690,000 deaths associated with it in 2019.

I also realize that probably depends largely on where you live.

Re: Vaccines should end the pandemic, despite the variants, say experts

#42

Post by xiphias2 »

2-tpg wrote: post #23
thepangolino wrote: post #4

These kind of pandemic tend to end themselves after about 20-30 months. We’re about half way there anyway.

You are correct. The pandemic may end after about 20-30 months, but this novel coronavirus will stick around. It is going to be a community virus, such as the Spanish flu turned into seasonal influenza. People pushed back hard against the experts when they started talking about preparing for herd immunity and 70%+ infected. So, this messaging has become more careful. A few months later the debate will turn to this be…

It's the first time we have mRNA vaccines available, which makes it much easier to update / mix different variations of the virus than earlier technologies. The mass production is still not optimized, but at least the incentives are huge at this point.

Re: Vaccines should end the pandemic, despite the variants, say experts

#43

Post by walterbell »

> the immune system has an array of other defenses... including antibodies that attack other parts of the virus, and, importantly, T-cells that attack the infected cells the virus hijacks in order to replicate. “What we’re seeing is that these variants don’t seem to affect T-cell immunity all that much and they [the T-cells] seem to be as effective in recognizing these variants as they do the original virus”

People with healthy immune systems, who have been exposed to SARS1 and other coronaviruses, have active T-cell defenses which recognize SARS-Cov-2 even without a vaccine.

> SARS-CoV-2 induces robust memory T cell responses in antibody-seronegative and antibody-seropositive individuals with asymptomatic or mild COVID-19, https://www.biorxiv.org/content/10.1101/2020.06.29.174888v1.... (June 2020)

> ..some people who have not been exposed to SARS-CoV-2 have preexisting reactivity to SARS-CoV-2 sequences ..previous exposure to widely circulating common cold coronaviruses might be involved .. preexisting reactivity against SARS-CoV-2 comes from memory T cells and that cross-reactive T cells can specifically recognize a SARS-CoV-2 epitope as well as the homologous epitope from a common cold coronavirus, https://science.sciencemag.org/content/370/6512/89 (Oct 2020)

Prior HN discussion on T-cells: https://hn.algolia.com/?prefix=true&query=t-cell

Re: Vaccines should end the pandemic, despite the variants, say experts

#44

Post by HPsquared »

Trasmatta wrote: post #25
stormbrew wrote: post #13

Earlier quoted context omitted.

The last pandemic with a death toll anything like (actually much worse than) COVID-19 is the still-ongoing HIV pandemic. It's entering its 40th year .

It's crazy to think about how HIV has killed some ~32 million people, and yet we rarely hear about it anymore. COVID probably won't even hit 4 million deaths (barring some much deadlier variant that we can't easily produce a new vaccine for).

We heard about it a lot when it was new and unknown. Now it's better understood, not so much.

Re: Vaccines should end the pandemic, despite the variants, say experts

#45

Post by SpicyLemonZest »

credit_guy wrote: post #19

What I don't understand is this: with tens of millions of people already vaccinated, why aren't we seeing a huge drive to collect plasma from vaccinated people with high level of antibodies? In the early days of the pandemic (about 1 year ago), I remember China sent a large amount of plasma to Italy. Why can't the US do the same now? The US is sitting on millions of AstraZeneca vaccines (that are not even approvad by…

The FDA won't allow convalescent plasma collection from vaccinated people (https://www.fda.gov/regulatory-information/search-fda-guidan...), on the grounds that their antibody response might be different than the response from a natural infection. (I don't know enough to judge whether or not this could be expected to cause practical issues.)

Re: Vaccines should end the pandemic, despite the variants, say experts

#46

Post by graeme »

walterbell wrote: post #43

> the immune system has an array of other defenses... including antibodies that attack other parts of the virus, and, importantly, T-cells that attack the infected cells the virus hijacks in order to replicate. “What we’re seeing is that these variants don’t seem to affect T-cell immunity all that much and they [the T-cells] seem to be as effective in recognizing these variants as they do the original virus” People w…

Don’t remember the study but pretty sure that cross reactivity thesis to common cold eventually didn’t pan out. Believe Derek Lowe wrote about it.

Re: Vaccines should end the pandemic, despite the variants, say experts

#47

Post by gizmo686 »

xadhominemx wrote: post #22
credit_guy wrote: post #19

What I don't understand is this: with tens of millions of people already vaccinated, why aren't we seeing a huge drive to collect plasma from vaccinated people with high level of antibodies? In the early days of the pandemic (about 1 year ago), I remember China sent a large amount of plasma to Italy. Why can't the US do the same now? The US is sitting on millions of AstraZeneca vaccines (that are not even approvad by…

Because it’s a lot easier to manufacture and distribute the vaccines

Vaccines and plasma serve 2 different purposes. A vaccine will provide long term protection, but do nothing to help a patient who is sick now [0]. In contrast, plasma will help a patient who is infected now, but provide no long term protection.

[0] Or, at least, the Covid vaccine has not been proven to do anything to help a patient who is sick now. There are cases (such as rabies) where getting vaccinated after being infected is still beneficial.

Re: Vaccines should end the pandemic, despite the variants, say experts

#48

Post by 2-tpg »

zamfi wrote: post #40
2-tpg wrote: post #23

Earlier quoted context omitted.

You are correct. The pandemic may end after about 20-30 months, but this novel coronavirus will stick around. It is going to be a community virus, such as the Spanish flu turned into seasonal influenza. People pushed back hard against the experts when they started talking about preparing for herd immunity and 70%+ infected. So, this messaging has become more careful. A few months later the debate will turn to this be…

> A few months later the debate will turn to this being leaky vaccines Made a bit more complicated by the fact that not all vaccines have the same properties here...somehow seems the mRNA vaccines do better at preventing shedding than the adenovirus-based ones [0]. [0]: https://www.nejm.org/doi/full/10.1056/NEJMoa2024671

Made way more complicated that it basically depends on what China did to restart Wuhan or Russia did to push through Sputnik (How much did these vaccines shed? Poor answers right now!). All of America can be mRNA while SARS-nCov keeps evolving elsewhere, just one flight away importing it. Surefire way to get vaccinated though :)

Re: Vaccines should end the pandemic, despite the variants, say experts

#49

Post by walterbell »

graeme wrote: post #46
walterbell wrote: post #43

> the immune system has an array of other defenses... including antibodies that attack other parts of the virus, and, importantly, T-cells that attack the infected cells the virus hijacks in order to replicate. “What we’re seeing is that these variants don’t seem to affect T-cell immunity all that much and they [the T-cells] seem to be as effective in recognizing these variants as they do the original virus” People w…

Don’t remember the study but pretty sure that cross reactivity thesis to common cold eventually didn’t pan out. Believe Derek Lowe wrote about it.

Lowe's Feb 2021 article was about antibodies, not T-cells, https://blogs.sciencemag.org/pipeline/archives/2021/02/10/do...

> Now, you can still make an argument that the T cell component of immunity might provide some protection after a previous coronavirus infection. The current study didn’t address this directly

Lowe's July 2020 article on T-cells, https://blogs.sciencemag.org/pipeline/archives/2020/07/15/ne...

> there are, in fact, people who have both CD4+ and CD8+ T cells that recognize protein antigens from the new coronavirus even though they have never been exposed to SARS, MERS, or the new virus. The paper speculated that this might be due to cross-reactivity with proteins from the “common cold” coronaviruses”, and raised the possibility that there might be a part of the population that has at least some existing protection against the current pandemic.

and

> patients who had caught SARS back in 2003 and recovered ... still have (17 years later!) a robust T-cell response to the original SARS coronavirus’s N protein ..This new work finds that these cross-react with the new SARS CoV-2 N protein as well

There is an open question in the Nature study, about prior, unknown animal coronaviruses which may have previously infected humans and conferred T-cell protection against SARS-CoV-2.

Re: Vaccines should end the pandemic, despite the variants, say experts

#50

Post by nradov »

credit_guy wrote: post #19

What I don't understand is this: with tens of millions of people already vaccinated, why aren't we seeing a huge drive to collect plasma from vaccinated people with high level of antibodies? In the early days of the pandemic (about 1 year ago), I remember China sent a large amount of plasma to Italy. Why can't the US do the same now? The US is sitting on millions of AstraZeneca vaccines (that are not even approvad by…

So far convalescent serum treatment using plasma donated by recovered COVID-19 patients hasn't been very effective. There were high hopes for this treatment at the beginning of the pandemic but so far study results have been disappointing. I doubt that serum from vaccinated people would be any more effective.
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