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Evaluating necessity of Covid-19 vaccination in previously infected individuals

medrxiv.org

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

#131

Earlier quoted context omitted.

Most authorities are downplaying natural immunity, despite evidence like this. The more widely this spreads, the more people will realize it's ok to rely on natural immunity, and to not blanket demonize those who are unvaccinated.

> to not blanket demonize those who are unvaccinated. Well, I'm currently in quarantine from my 4 month old and wife because an acquaintance refused to get vaccinated. "young people don't die from COVID" type mentality. I attended my brother's bachelor party - of which we all thought everyone was vaccinated. Turns out this person, not only refused to get vaccinated - but had COVID exposure and still decided to attend…

I'm talking about those who have recovered when I say natural immunity, not all unvaccinated.

Also, presumably, this person would now be as immune as someone who's gotten the vaccine, based on this study.

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

#132
post #17

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 key limitation of the study is that it's in the USA, where some of the most concerning variants are not as widespread.

For example, in Brazil there is evidence that the P.1 variant can lead to reinfections.

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

#133

Earlier quoted context omitted.

If this is rare enough, it could fall into the false positive rate of the COVID test they've previously done (i.e. while the test said they had COVID, they didn't)

The tests are designed to have high false positives because they have to bias toward few false negatives and there are no perfect tests. What gets me is that the negative result is the one bearing meaningful information but not the positive result, yet everyone mistakenly talks about positives as if they are far more informative than they actually are.

I'm not sure what test you have in mind, and I'm guessing that such tests with high false positive bias might exist, for example the antibody tests. It's very difficult to get a genuine false positive with a PCR-based test: whatever you're reading out should have the same sequence as the part of the virus you're sequencing. The only reasonable way to get a false positive is that you contaminate the sample, but I don't think that the possibility of contamination is part of the design in any of the commercially available tests.

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

#134
post #128

Why is it that so many people seem to be biased against evidence that our immune systems do a pretty good job? It's as if they want the vaccine to be the only thing that helps stop COVID.

Our immune systems are pretty amazing.

It's also good to help them along sometimes.

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

#135
One very important limitation is that this study does not take into account problematic variants such as P.1 and B.1.617

> Lastly, it is necessary to emphasize that these findings are based on the prevailing assortment of virus variants in the community during the study. It is not known how well these results will hold if or when some of the newer variants of concern become prominent.

Here in Brazil, I've heard news that the P.1 variant can cause reinfections but is still stopped by vaccines. This would point towards also vaccinating those who were already infected

https://jornal.usp.br/ciencias/primeira-dose-da-coronavac-e-...

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

#136
post #130

Earlier quoted context omitted.

well pack it up boys, lets not make this go viral on social media and just hope the "peers" organically pick this study to review over the next 6 months instead of some other study that appears to be more in the public interest and has more popular people behind it a while back I looked to see how long it actually took for the peer reviewed studies to come out for previous diseases and outbreaks, such as SARS 1. It w…

This study backs up the claim that people who had it don't need to get vaccinated. If it gets widely reported, that probably means fewer people will get vaccinated. So let me ask you this, what's the worst case scenario if they're right but had waited 6 months to get it reviewed? Then consider, what's the worst case scenario if they're wrong?

Good way to weigh things

I say this about every study

My main point is that it likely wont get peer reviewed, ever, unless it goes viral and people ask questions

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

#137
This is really good news. Whenever I see people talking about if previously infected people should be vaccinated, they always mention how we don't know how long protection lasts for previously infected people. This study includes this section:

    Duration of protection

    This study was not specifically designed to determine the duration of protection afforded by natural infection, but for the previously infected subjects the median duration since prior infection was 143 days (IQR 76 – 179 days), and no one had SARS-CoV-2 infection over the following five months, suggesting that SARS-CoV-2 infection may provide protection against reinfection for 10 months or longer.

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

#138
post #118
post #109

Earlier quoted context omitted.

My wife and I got COVID twice 9 months apart last year. The second time my wife ended up in the hospital. We both got vaccinated as soon as we could.

Wow really? Do you have positive test results that document the sequence of events? If so you should probably email these researchers or something. Bet they would be interested

There is already a decent understanding of documented reinfections. The first such cases came out a year ago, e.g.: https://en.yna.co.kr/view/AEN20200406006700320 , or https://www.jpost.com/health-science/israeli-doctor-reinfect... By the end of last summer there were clear documented cases with secondary infection from a different viral strain than the original one, e.g: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3681489 The original publication (and the reply that I cite that raises some concerns, but leaves the main argument in place) estimated that the protection from a past infection is about 83%, so significantly smaller than that from the 2-dose mRNA vaccines. https://www.bmj.com/content/372/bmj.n124/rr-0

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

#139

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…

How do you know your anti-vax friend was actually infected? I think a very real risk is that people decide they don't need the vaccine based on false-positive tests or otherwise mis-diagnosed illness. This study appears to be based on following up with a single hospital's own database of people who tested positive. But I imagine you would get different results if you just found a bunch of people and asked them to sel…

He was tested twice and came back positive both times - many people in his workplace had it. He 100% had it.

Agree on the self-reporting, but I guess my larger point is he already doesn't want to get the vax and people telling him that his natural immunity is not sufficient makes him even more distrustful since he does know enough about science/statistics to see that natural immunity is about equal with a vaccine as far as we can tell.

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

#140

Earlier quoted context omitted.

Most authorities are downplaying natural immunity, despite evidence like this. The more widely this spreads, the more people will realize it's ok to rely on natural immunity, and to not blanket demonize those who are unvaccinated.

> to not blanket demonize those who are unvaccinated. Well, I'm currently in quarantine from my 4 month old and wife because an acquaintance refused to get vaccinated. "young people don't die from COVID" type mentality. I attended my brother's bachelor party - of which we all thought everyone was vaccinated. Turns out this person, not only refused to get vaccinated - but had COVID exposure and still decided to attend…

> "young people don't die from COVID" type mentality.

What mentality is this? It is well known that young people are at extremely low risk of dying, even more so than the average person.

> He told us the day after being in close contact for 3 days, that he tested positive and had symptoms during our contact with him.

The problem wasn't that your acquaintance refused the vaccine. The problem is that he didn't stay home. You could say the same thing about the flu. If you have it, don't go to parties. Who goes to a party with a flu? A cold even?

I hardly think this guy is representative. There's also evidence that asymptomatic people don't spread COVID. This would mean that if they don't have symptoms, you won't get it, and if they do and they're like most people, they'll stay home which means no transmission.

> Of the unvaccinated [sic] people I know, this mentality is the large majority of them. They refuse to get vaccinated because they refuse to consider how their actions might actually impact someone else.

This seems unnecessarily hostile. Plenty of people don't want to be vaccinated either because they've had COVID and don't need it (this study isn't the first; Peter McCullough for example has spoken about other studies), they don't want to risk the potential side effects, including long term, of an experimental vaccine that is not technically approved by the FDA, ethical/religious reasons (the use of stem cell lines derived from aborted children during vaccine research, etc), and because the virus is not a serious threat to most people.

It is disturbing how the media is lumping those wary of the COVID vaccine in with antivaxers (~2% of the population; 98% of Americans get all common immunizations), COVID deniers, or "grandma killers". Let's not do that, as the OP recommends.

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