18 ms·

It's also worth noting that the most people still had antibodies effective against A.30-- just not as effective. So the existing antibody response would be exp

by mlyle 5y ago

It's also worth noting that the most people still had antibodies effective against A.30-- just not as effective. So the existing antibody response would be expected to slow infection and then the body is primed to broaden the variety and quantity of antibodies after infection. It's only a small portion of those receiving the AZ vaccine whose serum had no significant activity against A.30-- all of those with the mRNA vaccine did and most of those receiving AZ did.

cronix 5y ago
> It's only a small portion of those receiving the AZ vaccine whose serum had no significant activity against A.30-- all of those with the mRNA vaccine did and most of those receiving AZ did. How about those that received no vaccine, but have previously recovered from Covid? Is it an insignificant number because I rarely hear it discussed.
- armagon 5y ago
  I think it is due to politics that you don't hear this discussed; seemingly, nuance makes it more difficult to convey a message. The number of people who are known to have been infected is not insignificant, and the number who have been infected but it isn't known is much higher. (I thought estimated were that at least 4x as many people have had Covid as show up in the published results). There is every reason to expect that natural immunity (derived from a previous infection) is better (than that conferred by a vaccine), simply because the immune system will recognize the entire virus and not just the spike cell. This pre-print paper (https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...) concludes: "This study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant." If having pre-delta covid made it more likely that your immune system could face delta, then I think it would stand true for other variants, too.
  - cronix 5y ago
    Let's just say it was "on par" with a vaccine for the sake of argument, even if it is suggested it might be better/work more broadly. Is there a scientific reason, as opposed to political, why this would not exempt one from a mandated vaccine?
    - caconym_ 5y ago
      Since initial infectious doses and peak viral loads seem to vary wildly in people who've been infected, I would speculate that it's much easier to quantify vaccine-induced immunity in a public health context relative to so-called "natural immunity", since those initial variables can be tightly controlled. This is a practical matter for making consistent and effective public health policy, as well as a scientific matter (viz. establishing the relative effectiveness of various forms of immunity for diverse and uncertain infection scenarios). Experts in public health and/or infectious diseases, epidemiology, etc. may feel free to correct me if I'm substantially incorrect. However, for people who see the world through a lens that paints all public health policy with the brush of partisan politics, the distinction may be difficult to grasp.
      - OrvalWintermute 5y ago
        > Since initial infectious doses and peak viral loads seem to vary wildly in people who've been infected, I would speculate that it's much easier to quantify vaccine-induced immunity in a public health context relative to so-called "natural immunity", since those initial variables can be tightly controlled. I think you are missing the largest discriminator. The US Vaccines[1], and the related vaccines, are highly limited resistance specific to a spike protein only, perhaps with boosters, to a number of spikes seen. Total = 1, perhaps 2 if it includes a delta variant spike booster also. Natural immunity confers with it resistance to a number of different covid-19 viral proteins, not just the spike. We know Covid-19 has 29 proteins Now, we know that researchers saw these antibodies, as they were the ones that said, "all these antibodies could be the target of future vaccines", and the idea is there. However, we don't know the exactly count of antibodies to all these viral proteins, we just know of their existence from research. [2] But, to compare the strength of natural immunity to a vaccine is to fail at elementary math. However, I am not saying that people at a high risk from age, comorbidities, or both, should not take the vaccine. That is their own decision. On the other hand, the vast majority of the research indicates that natural immunity actually provides superior immunity from a breadth perspective, since a legacy vaccine protection is comparatively challenged against a mutated spike. [1] This is not true for all vaccines, merely "spike" vaccines. So, it wouldn't apply to an attenuated viral vaccine. However, attenuated vaccines do not prompt as strong an immune response. [2] https://pubmed.ncbi.nlm.nih.gov/32555388/ https://pubmed.ncbi.nlm.nih.gov/32555388/
- greg5green 5y ago
  They don't include the data in the paper, but they do have that data in the supplemental charts under "Convalescent". Looks like a similar dropoff as scene in people vaccinated with BNT162b2. It should be noted that this convalescent plasma was taken from ICU patients, not people that were asymptomatic or had minor symptoms.
- mlyle 5y ago
  There's convalescent plasma in the study we're all looking at. Looks like a similar difference. - People given AZ required 8.8x the concentration of their serum to neutralize A.30 vs. B.1 - For mRNA vaccines, this was 4.6x. - Convalescent plasma-- those infected-- this was 4.4x. - AZ dose 1, mRNA dose 2 was by far the smallest difference, 1.8x. I'd caution in reading too much into these numbers. Comparing titers in general between the groups in this study is problematic because of vastly varying times since infection/administration. And the size of the populations is small.
- nradov 5y ago
  It's a significant number. The CDC estimated that about 36% of Americans had been infected as of May (more by now). https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd... I recommend that everyone get vaccinated if they can, especially if they haven't had a confirmed infection. For most patients natural immunity provides protection as good or better than vaccination. https://www.medrxiv.org/content/10.1101/2021.09.12.21263461v1 https://www.medrxiv.org/content/10.1101/2021.09.12.21263461v...
- deleted 5y ago
  [deleted]
caeril 5y ago
I have an open question that I've never been able to find the answer to: What are the limits to the memory of our immune system? Surely there are limits, to the extent that our blood can only carry N number of Memory B cells, and those cells that still exist carry some degree of senescence, and we need M of them to mount an timely response to a recurrence of infection, how many protein antigens can our immune system actually remember and respond to over long periods of time?
- passivate 5y ago
  Short answer: nobody knows. In any case, I don't believe an answer is realistically even possible because we can't easily isolate all the other factors involved. Also, you'll have to consider affinity maturation and the cutoff for B-cell specificity for an antigen to clearly define what you even mean by 'remembering a protein antigen'. https://en.wikipedia.org/wiki/Activation-induced_cytidine_deaminase https://en.wikipedia.org/wiki/Activation-induced_cytidine_de... https://en.wikipedia.org/wiki/Affinity_maturation https://en.wikipedia.org/wiki/Affinity_maturation ^ and many more that will probably just end up amounting to a couple of years of study!

by mlyle 5y ago

cronix 5y ago

> It's only a small portion of those receiving the AZ vaccine whose serum had no significant activity against A.30-- all of those with the mRNA vaccine did and most of those receiving AZ did. How about those that received no vaccine, but have previously recovered from Covid? Is it an insignificant number because I rarely hear it discussed.

armagon 5y ago
I think it is due to politics that you don't hear this discussed; seemingly, nuance makes it more difficult to convey a message. The number of people who are known to have been infected is not insignificant, and the number who have been infected but it isn't known is much higher. (I thought estimated were that at least 4x as many people have had Covid as show up in the published results). There is every reason to expect that natural immunity (derived from a previous infection) is better (than that conferred by a vaccine), simply because the immune system will recognize the entire virus and not just the spike cell. This pre-print paper (https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...) concludes: "This study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the Delta variant of SARS-CoV-2, compared to the BNT162b2 two-dose vaccine-induced immunity. Individuals who were both previously infected with SARS-CoV-2 and given a single dose of the vaccine gained additional protection against the Delta variant." If having pre-delta covid made it more likely that your immune system could face delta, then I think it would stand true for other variants, too.
- cronix 5y ago
  Let's just say it was "on par" with a vaccine for the sake of argument, even if it is suggested it might be better/work more broadly. Is there a scientific reason, as opposed to political, why this would not exempt one from a mandated vaccine?
  - caconym_ 5y ago
    Since initial infectious doses and peak viral loads seem to vary wildly in people who've been infected, I would speculate that it's much easier to quantify vaccine-induced immunity in a public health context relative to so-called "natural immunity", since those initial variables can be tightly controlled. This is a practical matter for making consistent and effective public health policy, as well as a scientific matter (viz. establishing the relative effectiveness of various forms of immunity for diverse and uncertain infection scenarios). Experts in public health and/or infectious diseases, epidemiology, etc. may feel free to correct me if I'm substantially incorrect. However, for people who see the world through a lens that paints all public health policy with the brush of partisan politics, the distinction may be difficult to grasp.
    - OrvalWintermute 5y ago
      > Since initial infectious doses and peak viral loads seem to vary wildly in people who've been infected, I would speculate that it's much easier to quantify vaccine-induced immunity in a public health context relative to so-called "natural immunity", since those initial variables can be tightly controlled. I think you are missing the largest discriminator. The US Vaccines[1], and the related vaccines, are highly limited resistance specific to a spike protein only, perhaps with boosters, to a number of spikes seen. Total = 1, perhaps 2 if it includes a delta variant spike booster also. Natural immunity confers with it resistance to a number of different covid-19 viral proteins, not just the spike. We know Covid-19 has 29 proteins Now, we know that researchers saw these antibodies, as they were the ones that said, "all these antibodies could be the target of future vaccines", and the idea is there. However, we don't know the exactly count of antibodies to all these viral proteins, we just know of their existence from research. [2] But, to compare the strength of natural immunity to a vaccine is to fail at elementary math. However, I am not saying that people at a high risk from age, comorbidities, or both, should not take the vaccine. That is their own decision. On the other hand, the vast majority of the research indicates that natural immunity actually provides superior immunity from a breadth perspective, since a legacy vaccine protection is comparatively challenged against a mutated spike. [1] This is not true for all vaccines, merely "spike" vaccines. So, it wouldn't apply to an attenuated viral vaccine. However, attenuated vaccines do not prompt as strong an immune response. [2] https://pubmed.ncbi.nlm.nih.gov/32555388/ https://pubmed.ncbi.nlm.nih.gov/32555388/
greg5green 5y ago
They don't include the data in the paper, but they do have that data in the supplemental charts under "Convalescent". Looks like a similar dropoff as scene in people vaccinated with BNT162b2. It should be noted that this convalescent plasma was taken from ICU patients, not people that were asymptomatic or had minor symptoms.
mlyle 5y ago
There's convalescent plasma in the study we're all looking at. Looks like a similar difference. - People given AZ required 8.8x the concentration of their serum to neutralize A.30 vs. B.1 - For mRNA vaccines, this was 4.6x. - Convalescent plasma-- those infected-- this was 4.4x. - AZ dose 1, mRNA dose 2 was by far the smallest difference, 1.8x. I'd caution in reading too much into these numbers. Comparing titers in general between the groups in this study is problematic because of vastly varying times since infection/administration. And the size of the populations is small.
nradov 5y ago
It's a significant number. The CDC estimated that about 36% of Americans had been infected as of May (more by now). https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burden.html https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/burd... I recommend that everyone get vaccinated if they can, especially if they haven't had a confirmed infection. For most patients natural immunity provides protection as good or better than vaccination. https://www.medrxiv.org/content/10.1101/2021.09.12.21263461v1 https://www.medrxiv.org/content/10.1101/2021.09.12.21263461v...
deleted 5y ago
[deleted]

caeril 5y ago

I have an open question that I've never been able to find the answer to: What are the limits to the memory of our immune system? Surely there are limits, to the extent that our blood can only carry N number of Memory B cells, and those cells that still exist carry some degree of senescence, and we need M of them to mount an timely response to a recurrence of infection, how many protein antigens can our immune system actually remember and respond to over long periods of time?

passivate 5y ago
Short answer: nobody knows. In any case, I don't believe an answer is realistically even possible because we can't easily isolate all the other factors involved. Also, you'll have to consider affinity maturation and the cutoff for B-cell specificity for an antigen to clearly define what you even mean by 'remembering a protein antigen'. https://en.wikipedia.org/wiki/Activation-induced_cytidine_deaminase https://en.wikipedia.org/wiki/Activation-induced_cytidine_de... https://en.wikipedia.org/wiki/Affinity_maturation https://en.wikipedia.org/wiki/Affinity_maturation ^ and many more that will probably just end up amounting to a couple of years of study!