Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Evaluating necessity of Covid-19 vaccination in previously infected individuals

medrxiv.org

Post reply on HN
Print view View original

71–80 of 361 posts

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#71

Post by epgui »

AndrewBissell wrote: post #56
epgui wrote: post #53

Earlier quoted context omitted.

The person who told your brother this is either a non-expert, or some expert who for some reason is giving medical advice which is incompatible with the scientific consensus (this would really boggle my mind). PS.: my 99.99% refers to the state of human knowledge and is more about what experts in the field know than what the general public knows.

> some expert who for some reason is giving medical advice which is incompatible with the scientific consensus (this would really boggle my mind) Doesn't really seem that mind boggling to me. The clear public health impetus at this point is simply to get shots in as many arms as possible. We've already had Fauci openly admit that he gave guidance against masking and low-balled herd immunity threshold estimates becaus…

I think what I was referring to, and the examples you're giving, are very different. The early advice against masks were the best advice public health could give, with the information that was available (even among experts) at the time. I would give the same advice as Fauci at the time. There are a bunch of factors to consider: behavioural (people having a false sense of security and taking greater exposure risks, or people not using masks properly and actually increasing their risk), medical (at the time, the benefits of non-N95 masks were not as clear as they are now) and system-level (supply chain issues were real, many countries had a really hard time getting procurement of basic PPE for hospitals... and you want to make sure you prioritize hospital workers over the general population)

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#72

Post by ds206 »

mikedilger wrote: post #10
mlyle wrote: post #8

Note this is to inform public health / prioritization in the short term. (Which is less necessary places like the US where there is excess vaccine supply). We know that past infection greatly reduces risk (and this helps quantify it). At the same time, vaccination is thought to cause a much broader and more durable immune response than natural infection. We'd like people who were previously infected to get vaccinated…

Not that I have any knowledge on this subject, but why would a vaccine that stimulates the creation of a bit of spike protein create a "much broader and more durable immune response" than the actual virus which I presume creates a hell of a lot more of that exact same spike protein? Genuinely curious, because my simpleton assumption would be the opposite.

You got that backwards, my friend

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#73

Post by tootie »

epgui wrote: post #21

Any other result would have been surprising. Why is this interesting, beyond just confirming what we were already 99.99% certain we knew? -- biochemist

There were stories of reinfection happening. Also variants. Also, every covid study of every kind is getting an enormous amount of attention and resources

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#74

Post by epgui »

AndrewBissell wrote: post #62
handmodel wrote: post #52

Earlier quoted context omitted.

My one anti-vax friend (who I make fun of constantly for not getting it) is constantly bombarded with people telling him that his previous infection doesn't give him any immunity. I already knew that was false - and I think he knew that too. It probably fed into his (motivated) reasoning to hold out this long if people are telling him so much information they know to be untrue. Still, I don't see how public health wo…

> Still, I don't see how public health would benefit from not recommending shots to everyone as there is no downside The VAERS data suggests there are numerous groups at very low risk from Covid for which this may not be the case.

This is a dubious claim, and is a frequent anti-vaxx/vaccine-hesitancy talking point.

VAERS data needs to be interpreted with special care. It's not equivalent to a safety study with a proper experimental design. It has a whole lot of legal and administrative context to account for.

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#75

Post by rolph »

mlyle wrote: post #63
tomp wrote: post #9

Earlier quoted context omitted.

> vaccination is thought to cause a much broader and more durable immune response than natural infection Why? Is there any data to support this assertion? If anything, being ill (symptomatic) means the viral load was high in the body, so the immune system response should be as well, and in addition, infection should cause the immune system to produce antibodies to all parts of the virus, not just the spike protein, a…

Yes! https://www.nejm.org/doi/full/10.1056/NEJMc2032195 Shows a slow decay in neutralizing antibody titers, with a greater degree of viral inhibition months later than convalescent plasma at a month. "At day 119, the binding and neutralizing GMTs exceeded the median GMTs in a panel of 41 controls who were convalescing from Covid-19, with a median of 34 days since diagnosis (range, 23 to 54)." Note that antibodies to…

neutralizing antibodies will give protection against cell entry to the degree they saturate the binding kinetics between receptor and ligand. non neutralizing does not mean ineffective, as ^any^ antibody is a lable that will provoke a complement based immune response, further leading to Tcell based production of antibodies that also include Ab that will bind to domains of spike that are essential to cell entry

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#76

Post by epgui »

tootie wrote: post #73
epgui wrote: post #21

Any other result would have been surprising. Why is this interesting, beyond just confirming what we were already 99.99% certain we knew? -- biochemist

There were stories of reinfection happening. Also variants. Also, every covid study of every kind is getting an enormous amount of attention and resources

Given a large enough sample size, reinfections are pretty much guaranteed to happen. These are not incompatible with each other.

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#77

Post by Panther34543 »

Animats wrote: post #59

Well, that's encouraging. Now we have data for about 5 months on that. About the same on vaccinated individuals. In a year, we'll know more about how long immunity lasts, and if and when booster shots will be needed.

> Now we have data for about 5 months on that.

What do you mean? Immunity of naturally infected individuals has been tracked far longer than five months, with both empirical evidence of lasting immunity along with obvious community evidence.

Do you know why the infection rate in San Francisco was so low? There was already a ton of natural immunity due to community spread. The majority of my office in downtown SF caught COVID in January 2020, which was confirmed by negative influenza A & B tests followed by positive antibody tests once they were made available.

What is particular disturbing to me is that, despite the fact that the CDC estimates total infections to be over a third of the U.S. population (and that estimate only accounts for February 2020 onward and doesn't include last two months), natural immunity is never, ever discussed by policy makers. Why? That's a massive amount of natural immunity that continues to be purposely ignored.

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#78

Post by mlyle »

mikedilger wrote: post #10
mlyle wrote: post #8

Note this is to inform public health / prioritization in the short term. (Which is less necessary places like the US where there is excess vaccine supply). We know that past infection greatly reduces risk (and this helps quantify it). At the same time, vaccination is thought to cause a much broader and more durable immune response than natural infection. We'd like people who were previously infected to get vaccinated…

Not that I have any knowledge on this subject, but why would a vaccine that stimulates the creation of a bit of spike protein create a "much broader and more durable immune response" than the actual virus which I presume creates a hell of a lot more of that exact same spike protein? Genuinely curious, because my simpleton assumption would be the opposite.

Many reasons, that I don't fully understand. A few are: adjuvant properties of the vaccine, and the fact that there's a booster dose given, and that there's a whole ton of spike protein made and not many other targets.

But the reasons don't really matter -- studies like https://www.nejm.org/doi/full/10.1056/NEJMc2032195 have shown those vaccinated have significantly higher neutralizing antibody titers in their plasma than convalescent plasma, and slow decay of this response.

Of course, this isn't perfect evidence, as it is just the neutralizing antibody responses and the adaptive immune system response is much more complicated than this single measure.

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#79

Post by mlyle »

jjgreen wrote: post #14
tomp wrote: post #9

Earlier quoted context omitted.

> vaccination is thought to cause a much broader and more durable immune response than natural infection Why? Is there any data to support this assertion? If anything, being ill (symptomatic) means the viral load was high in the body, so the immune system response should be as well, and in addition, infection should cause the immune system to produce antibodies to all parts of the virus, not just the spike protein, a…

"it is thought" I guess comes from nonsense like this: https://www.huffingtonpost.co.uk/entry/does-the-vaccine-give...

It comes from nonsense like this: https://www.nejm.org/doi/full/10.1056/NEJMc2032195

Re: Evaluating necessity of Covid-19 vaccination in previously infected individuals

#80

Post by starfallg »

variaga wrote: post #17
mikedilger wrote: post #10

Earlier quoted context omitted.

Not that I have any knowledge on this subject, but why would a vaccine that stimulates the creation of a bit of spike protein create a "much broader and more durable immune response" than the actual virus which I presume creates a hell of a lot more of that exact same spike protein? Genuinely curious, because my simpleton assumption would be the opposite.

The rough theory - as I understand it - is that the virus is composed of other things as well as the spike protein e.g. the proteins in the viral shell. The immune system can learn to attack _whatever_ foreign materials it encounters. So a person that clears the infection might have a strong immune response to the spike protein, but the response could also be focused on some other part of the virus (or a mixture of d…

A 2-dose vaccination regime (separated by 8-12 weeks) also gives our immune system time to build up the spike protein. An actual infection doesn't last as long and hence our immune system doesn't process it in the same way.
Post reply on HN