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Israeli Study: Natural Immunity Is 13x Stronger Than Pfizer Covid Shots

126 points by nostromo 5y ago

_Microft 5y ago
That's good news for people who have already recovered from Covid. We should definitely take that into account for policies around opening up again, i.e. by treating recovered people like vaccinated people. Beside that it is of little use, is it? "Get Covid to be better protected from Covid" doesn't make a lot of sense to me, at least.
- nostromo 5y ago
  People should obviously get vaccinated, yes. It does suggest that the vaccines could be improved to be even more effective. It’s also interesting that the people most resistant to delta are people that were both infected and vaccinated.
  - lottin 5y ago
    I seem to recall someone suggested that since a large percentage of the population is vaccinated and are therefore protected against severe covid, we should now actually try to catch it to develop a natural immunity to the virus.
    - _Microft 5y ago
      I had skimmed and summarized such an article (submitted by someone else) a few weeks ago. I'm not sure that I would actually agree with it though. You can find it here: https://news.ycombinator.com/item?id=28109055 https://news.ycombinator.com/item?id=28109055
    - throwawaycities 5y ago
      The “problem” is that vaccinated people with the virus but experiencing no symptoms is that they still spread it to both unvaccinated and vaccinated alike. While many might not feel sympathy for the unvaccinated, a small % can’t get the vaccination, and there will still be that % of vaccinated people that do have a bad health outcome.
      - nradov 5y ago
        At this point the Delta variant is so contagious that there will be no significant herd immunity effect to protect unvaccinated individuals. They're going to get exposed and infected eventually no matter what we do. https://www.businessinsider.com/delta-variant-made-herd-immunity-not-possible-astrazeneca-developer-2021-8 https://www.businessinsider.com/delta-variant-made-herd-immu...
        deleted 5y ago
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        mlyle 5y ago
        Maybe. I quibble with "no significant herd immunity." I'm in an area with a very high vaccination rate (>87% of those over age 12 having had at least one dose, >80% fully vaccinated). Our case counts are a fraction of the rest of the country. The country's rates would be expected to be 3x lower if we could simply extrapolate my locale's rates among vaccinated and unvaccinated people to those fractions of the population in the rest of the country. This seems to hold up in other high-vaccination regions, though obviously there are confounds. The phase delay and greatly decreased count even makes me speculate that my locale (which is still using some mitigations) may be operating in a regime of Rt < 1.0 right now, and all case chains (slowly) geometrically decay from outside introductions from travel, etc. And we expect immunity to improve further, from kids being vaccinated and from more unvaccinated people getting infected. Maybe this isn't true. But we seem, at the least, to be experiencing some benefit beyond the direct benefits for vaccinated individuals.
        nradov 5y ago
        Case counts are meaningless as they largely reflect the level of testing. In most places there's not enough random population testing going on to get accurate infection counts. In the US the CDC estimates that infections are about 4× officially counted "cases".
        mlyle 5y ago
    - pengaru 5y ago
      It's not a hare brained idea, and it's been presented in the msm recently like @ https://www.bbc.co.uk/news/health-58270098 https://www.bbc.co.uk/news/health-58270098
    - foogazi 5y ago
      > we should now actually try to catch it to develop a natural immunity to the virus. We should catch it to get immunity so we don’t catch it ? I don’t get your thinking here
- trhway 5y ago
  >Beside that it is of little use, is it? "Get Covid to be better protected from Covid" doesn't make a lot of sense to me, at least. "Get Covid to better protect others from Covid" - Stronger immunity results in less chances to get infected again and less viral spread when infected. Ie. given that existing vaccines don't protect much against infection by delta, and that once infected the vaccinated spread the virus like unvaccinated, one can see that the people with natural immunity are much more preferable to have around than vaccinated.
  - teachrdan 5y ago
    >once infected the vaccinated spread the virus like unvaccinated You are spreading disinformation. Vaccinated people who do get sick are less likely to spread the virus, and have a high viral load in their system for a shorter duration: --- A vaccinated person may have the same viral loads as an unvaccinated person, but that high level of virus lasts only three to four days compared with an unvaccinated person who could be contagious for up to 10 days, said Suresh Mittal, professor of virology at Purdue University’s College of Veterinary Medicine. “Individuals who are vaccinated have a good immune response. If they get in contact with people who are infected, they might get infected, but the majority may not transmit,” he said. https://www.usatoday.com/story/news/health/2021/08/11/covid-transmission-among-vaccinated-unvaccinated-what-experts-say/5488398001/ https://www.usatoday.com/story/news/health/2021/08/11/covid-...
    - trhway 5y ago
      >Vaccinated people who do get sick are less likely to spread the virus https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v1 https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v... "We find no difference in viral loads when comparing unvaccinated individuals to those who have vaccine “breakthrough” infections. " >that high level of virus lasts only three to four days compared with an unvaccinated person who could be contagious for up to 10 days may be. Yet it is the first days what matter until one notices that s/he is ill. And the article you cite has gems like this >Cases of breakthrough infections among the vaccinated remain rare. Where is for example in MA - with 65% vaccination rate - out of the 1400 new daily infections the 400+ are breakthrough : https://www.nbcboston.com/news/coronavirus/mass-has-3098-new-breakthrough-cases-7-more-covid-deaths-among-vaccinated/2475214/ https://www.nbcboston.com/news/coronavirus/mass-has-3098-new... And there is similar data from highly vaccinated places like UK, Israel, Singapore.
- Gibbon1 5y ago
  Well you have two options. Either 1) You force everyone to get tested for Covid. Then vaccinate everyone who tests negative. 2) Or you just vaccinate everyone knowing those that had it will just end up with stronger immunity. Seems like 2 is the cheapest most straightforward option.
  - nradov 5y ago
    Those aren't the only options. It would be unethical to force testing on everyone.
    - Gibbon1 5y ago
      You can't trust people to self report having covid. Because a very high percentage will lie about it. Same as rules that allow vaccinated people to not wear masks. Unvaccinate people will up and lie about being vaccinated.
    - bserge 5y ago
      It's unethical to withhold mental health medication, too, but strangely no one gives a fuck about that.
    - retrac 5y ago
      We don't need to. People could be given the option of testing, or of going into isolation for the incubation period. Several countries had great effect from ordering a lockdown and testing the entire population over a day or two, releasing those who are negative from lockdown, and repeating this process multiple times in badly affected areas. Slovakia did this and it seems to have been extremely effective, though obviously not enough to eradicate it: https://www.bmj.com/content/371/bmj.m4761 https://www.bmj.com/content/371/bmj.m4761
      - nradov 5y ago
        Irrelevant. What appeared to work temporarily in Slovakia last year has no bearing on management of the more contagious Delta variant. Community transmission in most countries is so widespread now that there's simply no practical way to isolate so many people. It's just too late for that to work.
- H8crilA 5y ago
  Wait, which country isn't treating the recovered like the vaccinated? I thought it's standard, at least in Europe.
  - aqme28 5y ago
    I know for my flight from the US to Europe, I need proof of vaccination. Proof "of immunity" is not sufficient.
    - H8crilA 5y ago
      Weird. I guess it's different for non citizens. https://ec.europa.eu/info/live-work-travel-eu/coronavirus-response/safe-covid-19-vaccines-europeans/eu-digital-covid-certificate_en https://ec.europa.eu/info/live-work-travel-eu/coronavirus-re...
  - nostromo 5y ago
    That’s not the case in the US.
  - dogma1138 5y ago
    In Europe you can get a certification only if you had a positive PCR result in the past 180 days. So if you want to travel right now freely you need to be double dosed unless you have recovered recently.
- marlo111 5y ago
  I've had COVID multiple times since this all started, no symptoms, I have positive tests and Antibodies. The pressure of getting the vaccine finally got to me. I didn't want to get it. Coming from a science background, my understanding is that my body is neutralizing COVID before it can cause any clinically expressed inflammation. The media, politics, and big pharma need to stay out of medicine, but it's too late.
deleted 5y ago
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phenkdo 5y ago
Isn't this literally survivorship bias?
- tomesch1982 5y ago
  That was also my first thought.
- deleted 5y ago
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- defaulty 5y ago
  Sure, but for someone who has already /survived/, it's worth knowing the value of those antibodies. And it's worth knowing that governments should not attack those survivors further for "not getting vaccinated" when they already have antibodies. Worth noting that I'm not anti-vaccine but there's not enough focus on natural immunity. And I'm not encouraging people to forego vaccines and to go lick doorhandles
  - johnchristopher 5y ago
    > And it's worth knowing that governments should not attack those survivors further for "not getting vaccinated" when they already have antibodies. Does delta change that ? Is natural immunity from a previous variant as effective against delta ?
    - JumpCrisscross 5y ago
      > Is natural immunity from a previous variant as effective against delta? This study's data come from during Israel's Delta-variant surge, so yes.
- haroldship 5y ago
  1) possibly, but in Israel nearly all deaths are over 60 but most infections are not so maybe not so much 2) depends on the question: if you ask if you should get vaccinated or get covid, then yes. If you ask whether it’s as safe to be around a recovered as a vaccinated, then not really
nostromo 5y ago
Preprint (awaiting peer review) study: https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...
tomesch1982 5y ago
Sounds a bit like survivor bias. People who have already recovered once (and not died) are more likely to recover a second time (and not die). In the control group, people who have never had the virus, some have a harder time with it. I hope this gets taken into account.
- iab 5y ago
  Exactly - “for those who didn’t die”
- tim333 5y ago
  Thankfully quite a small percentage of covid patients die. Certainly not enough for a 16x difference.
  - MatteoFrigo 5y ago
    You cannot conclude anything about the 16x difference (TFA says 13x, by the way) from the number of dead patients. As a made up example to illustrate this point, assume that people are either "lucky" or "unlucky". Unlucky people die when they get the virus. Lucky people never die. Assume that one person per million is unlucky, and assume that the vaccine does absolutely nothing. Then this experiment on one million people would find one death in the vaccinated and zero deaths in the control group, inferring that natural immunity is infinitely better.
  - CharlesW 5y ago
    Why do you believe "a small percentage of COVID-19 patients die" (which is only true compared to, say, Ebola) has any relevance to the results of this study?
    - tim333 5y ago
      The argument I was replying to is the numbers are skewed by survivorship bias, but given >98% of people survive that's only going to skew the numbers 2% or so not 600% or whatever.
  - 5y ago
blueyes 5y ago
Does this mean that the ideal path for maximum immunity is to get vaccinated and then get a breakthrough infection?
- ianlevesque 5y ago
  Yes, which is basically how this ends 5 years from now. We’re probably all going to get exposed, but get your vaccine first!
  - deleted 5y ago
    [deleted]
- ardit33 5y ago
  Yeah, Unless you are one of the unlucky ones... The fact it is that the virus will be around with us for a while, and everyone will probably get it at some point. Vaccination will help when dealing with it.
- johnchristopher 5y ago
  This should be compared to a third boost of a different vaccine.
- hurlathroway 5y ago
  It sounds like that might be our endgame now. If covid becomes endemic, which may be inevitable, then the only question is whether you want your body to be prepared for its first infection or not. I wonder if this could end up like the 'common cold' coronaviruses, where future generations build up immunity through exposure very early in life, resulting in mild infections in adulthood. That would beg an interesting question: how lethal would 'common colds' be if we hadn't all been exposed to them multiple times throughout our childhoods?
  - dataflow 5y ago
    > 'common cold' coronaviruses I think you mean rhinoviruses?
criticaltinker 5y ago
This pre-print study has been discussed a few times on HN recently [1][2]. Many people are commenting that this paper is flawed by survivorship bias. While it would be useful to know the "cumulative" risk of SARS-CoV-2 infection, the fact is that a vast majority of people survive initial infection. So it is also useful to know the pure risk associated with reinfection - to inform public health policy and vaccine research. That is why the purpose of this research is to evaluate the risk of reinfection by directly comparing the effectiveness of natural immunity and vaccine-induced immunity in the context of the delta variant, which has mutations that confer partial immune escape. This research is significant because it is one of the first and largest studies to do so. [1] https://news.ycombinator.com/item?id=28327482 https://news.ycombinator.com/item?id=28327482 (350 comments) [2] https://news.ycombinator.com/item?id=28317866 https://news.ycombinator.com/item?id=28317866 (226 comments)
dredmorbius 5y ago
Natural immunity comes with a 10--25x greater risk of death, possibly much higher (see update) by COVID itself. (The risk from the vaccine, without a Covid infection, is effectively nil based on hundreds of millions of doses administered.) Natural immunity comes with a ~9x greater risk of hospitalisation, again from Covid itself. There's effectively no risk from the vaccine, again with hundreds of millions of doses administered. Among adults aged 65–74 years, effectiveness of full vaccination for preventing hospitalization was 96% for Pfizer-BioNTech, 96% for Moderna, and 84% for Janssen COVID-19 vaccines; among adults aged ≥75 years, effectiveness of full vaccination for preventing hospitalization was 91% for Pfizer-BioNTech, 96% for Moderna, and 85% for Janssen COVID-19 vaccines. https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e3.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e3.htm Note that "natural herd immunity" doesn't come without a near-total population infection rate, with a large number of deaths, prolonged medical care, and long-term health consequences. The vaccine-based risks are far, far, far lower. There's also quite likely a much higher likelihood of long-term Covid symptoms or consequences. This information is interesting, but a poor basis on which to shift policy from vaccination to infecting the entire population and blessing the survivors. Update: the article is also a dupe of an earlier substantial discussion: https://news.ycombinator.com/item?id=28307224 https://news.ycombinator.com/item?id=28307224 (260 comments). US CDC reports an 0.0016% fatality rate from all causes for vaccinated individuals. That's 100x lower than the incident fatality rate of 0.1% suggested by multiple countries with excellent Covid surveillance and reporting systems. Note that many early vaccine recipients were elderly (65+) and would have a higher natural death rate than the general population. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/ad... I've clarified the vaccine vs. natural infection risks based on criticism of unclear language.
- didibus 5y ago
  It's good as a combination I think. You can get the vaccine to prevent major illness and death, and if you catch Covid as a breakthrough case, you'd be even more strongly immune thereafter, hypothetically.
- cwalv 5y ago
  How does it compare to natural immunity from a "breakthrough infection"? If risk of hospitalization is low and following immunity is stronger, that seems relevant to whether we some should get booster shots, esp when so many haven't been able to get their first round
bigcorp-slave 5y ago
Non-peer reviewed study being flogged by the right wing to push an anti-vaccine agenda, upvoted on Hacker News. How is today unlike any other day? Yawn. Worse, the guy who’s posting this has been spreading COVID misinformation on this site for literally years.
- deleted 5y ago
  [deleted]
daenz 5y ago
Is there a difference in the immunity provided? What I mean is, does natural immunity do better at suppressing the transmission of covid19 than vaccine immunity? If that is the case, wouldn't that be an argument for encouraging every low-risk healthy person to develop natural immunity to suppress the spread to immunocompromised people?
dataflow 5y ago
Important note: this is for the delta variant. Vaccines appear to be less effective* against delta in general, and previous comparisons (like those that said vaccines are more effective [1]) were regarding earlier variants. I have yet to see anything that confirms that the conclusions of the study would be similar for other variants. (If you have any links supporting that, please do share.) [1] https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... * But still pretty darn effective. To be abundantly clear: this was in no way meant to suggest that it's a good idea to avoid getting vaccinated...
- pplante 5y ago
  Less effective at preventing infection, no less effective in preventing death or hospitalizations. We need to get everyone vaccinated to avoid the crush on our healthcare systems. Hospitals are facing bed shortages because many have given up on basic precautions in the USA.
user764743 5y ago
The data was posted as a preprint article on medRxiv, and hasn’t yet been reviewed by other researchers. Would take it with a grain of salt.
dredmorbius 5y ago
Note that this is a syndicated article from The Federalist a political opinion outlet, not a medical journal. The submitted link is from "ThinkCivics", a partisan news aggregator. The source is https://thefederalist.com/2021/08/27/israeli-study-natural-immunity-is-13x-stronger-than-pfizer-covid-shots/ https://thefederalist.com/2021/08/27/israeli-study-natural-i... Both sources are highly partisan and not especially given to an unbiased and facts-based interpretation or presentation of issues.
muttantt 5y ago
I know this is a controversial take, but it should be in our national interest to get young children exposed and gain natural immunity, and avoid giving them the vaccine we have so little long-term data on. According to the CDC, 450 kids (0-18yo) died from Covid-19 since Jan 2020. A total of 4.6M kids tested positive since then. In the much shorter 2017-2018 Flu season, ~650 kids (0-17) died. We really have to keep things in perspective.
- bluedevil2k 5y ago
  We don’t have any long term data on Covid infection either. Why risk children’s lives?
  - muttantt 5y ago
    Because the vaccine is a risk factor on its own as well. Do you not agree with that?
    - JumpCrisscross 5y ago
      > vaccine is a risk factor on its own as well We have evidence, in adults, of long-term effects from Covid. These effects aren't benign, either, e.g. permanent damage to the brain's grey matter. We have zero evidence of long-term side effects from the vaccine. Ceteris paribus, infection is riskier than vaccines to adults. (I can think of zero diseases for which the vaccines are fine for adults and harmful to children and whose infections are harmful for adults and fine for children.) This study is compelling evidence for creating an analog to the vaccine passport for the provably previously infected. It is not good evidence for intentional infection.
    - bluedevil2k 5y ago
      No, not at all, if you understand how the vaccine works you wouldn’t either.
    - lamontcg 5y ago
      The vaccine risk is strictly a subset of the viral risk. Getting the virus entails getting a lot more of the spike mRNA pumping out a lot more spike protein along with all the rest of the viral machinery and real infectious virions, infecting more cells than just in the muscle of your arm, attacking your heart, lungs, kidneys, etc. Getting the virus is always going to be worse, for everyone, than getting the vaccine. Which is also why people refusing to get the vaccine because they've been infected is dumb, because they already beat everything in the vaccine.
forty 5y ago
I'm curious, couldn't we just get a shot of virus after the 2 Pfizer shots to benefit from this stronger immunity?
andy_ppp 5y ago
Is there any case for offering people a dose of COVID-19 at the peak of their vaccine immunity and scheduled when people can self isolate? It just seems we’re all going to get a variant of COVID at some point before it becomes like another flu that occurs yearly?
viburnum 5y ago
What if you get vaccinated and then get a breakthrough infection? How's your immunity then?
- didibus 5y ago
  From what I've seen, this is where we seem to have lucked out. In that if you get Covid as a vaccinated person, it will still dramatically reduce your chances of being hospitalized or dying from it. > August 25, 2021 — The Health Department today released new data on vaccine effectiveness and breakthrough cases, hospitalizations and deaths. Between January 17 and August 7, 2021, 96.1% of COVID-19 cases, 96.9% of COVID-19 hospitalizations, and 97.3% of COVID-19 deaths in New York City were in people who were unvaccinated or not fully vaccinated. Additionally, for the same time period, 0.33% of fully vaccinated New Yorkers have ever been diagnosed with COVID-19, 0.02% have been hospitalized with COVID-19, and 0.003% have died due to complications with COVID-19. > from August 7, unvaccinated New Yorkers are 3.1 times more likely to get COVID-19 than fully vaccinated New Yorkers. Additionally, unvaccinated New Yorkers are almost 10 times more likely to be hospitalized with COVID-19 than those who are fully vaccinated You can read more here: https://www1.nyc.gov/site/doh/about/press/pr2021/health-department-releases-data-covid-19-vaccine-effectiveness.page https://www1.nyc.gov/site/doh/about/press/pr2021/health-depa...
sergiotapia 5y ago
If you're young and not fat, why would you get the vaccine? Just lose weight and exercise. If you're a child, why would your parents want you to get vaccinated if there's no risk at all? I hope these studies are conclusive once and for all.
- bserge 5y ago
  I agree if you sign a waiver saying you get no healthcare in the rare case that your infection requires hospitalization. That's my stance on prescription medication, too, in case you think I'm just being an asshole about CV. I'd sign a waiver for the freedom to buy antidepressants.
throwaway5752 5y ago
I want to ask about source material for a minute. What is ThinkCivics? Why is it reasonable second-hand source for analysis of a non-peer reviewed article? Does it have editorial biases? I am asking sincerely. It is a new site to me, and I don't know if it is a trustworthy source of information. The site is also unresponsive at the time I'm writing this.
- yehosef 5y ago
  Anything that questions the value of vaccines should be suspected as misinformation, regardless of the source.
  - fileeditview 5y ago
    Is that sarcasm?
    - yehosef 5y ago
      No, unfortunately.
- zaik 5y ago
  The text is copied from a website called "The Federalist": https://en.m.wikipedia.org/wiki/The_Federalist_(website) https://en.m.wikipedia.org/wiki/The_Federalist_(website)
  - throwaway5752 5y ago
    It's plagiarized?
    - zaik 5y ago
      No, the original source is stated at the bottom of the text. The website seems to be a news areggator with a focus on US conservative talking points.
- anigbrowl 5y ago
joelbondurant 5y ago
This must be taken down, all Science must be ordained by the USA Fact-Check Algorithm of the Science Ministry. Communists unite in diaper face unity!
bserge 5y ago
Yeah, whatever. How long does immunity last? I had Covid in February, kinda curious if I still have the antibodies. But I'm not paying 80 Euros to find out, unless you crowdfund me :D
- nradov 5y ago
  There's more to immunity than antibodies. Even if you don't have detectible levels of antibodies your memory T cells may be providing some protection. Many blood donation centers conduct free antibody tests for donors so you might want to check if that's an option.
rgbrenner 5y ago
can we change the URL to the paper?[0] The "article" is just blog spam consisting of a few quotes from the abstract of the paper. And I had to go find a cached version because the site was down. 0. https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...
- jsnell 5y ago
  The paper was also discussed on HN three days ago (245 comments): https://news.ycombinator.com/item?id=28307224 https://news.ycombinator.com/item?id=28307224
joelbondurant 5y ago
Driving through Rocky Mountain National Park is 45 times more lethal than staying home, so I'm wearing a mask to protect my shadow.
m3kw9 5y ago
But first you would need to get infected to acquire such immunity. Pretty much defeats the purpose when it could cause severe outcomes which you wanted to avoid in the first place. But rather, even though you may get the infected after vaccination, it will lower the chance of severe outcome by nearly as much. I’d rather acquire natural immunity via the vaccine route.
anigbrowl 5y ago
By the famed medical experts at the Federalist ◔_◔ I think for an assertion like this it's better to link directly to the study preprint rather than a tendentious summary of it.
fastaguy88 5y ago
Some of the numbers in the tables seem strange to me. Looking at the participants, it is hard to understand how the mean and sd of the ages and age distributions can be exactly the same. Moreover, apparently the odds of being hospitalized are 160-times greater for vaccinated vs unvaccinated second infection individuals. Perhaps the dramatic differences are due to very low numbers - I did not see the raw numbers for symptomatic infection and hospitalization. But if I were reviewing this paper, I would wonder how they got their age distributions to match so closely.
- jsnell 5y ago
  It's a matched cohort study. They're starting with a large population in both of their target groups, and then picking pairs of demographically identical people (e.g. age, sex, location), one from each group, for the study. So you'd certainly expect the age distributions to match up exactly. It'd be more worrying if criteria they weren't doing the matching by also were exactly identical. That's not the case, all kinds of secondary characteristics such as comorbidities are roughly but not exactly the same.
  - fastaguy88 5y ago
    Thanks. One wonders how closely they matched time of infection and local infection rate.
    - jsnell 5y ago
      They couldn't have matched the time of infection, since not everyone in the study was (re-)infected during the study period. The point of the study was to see if there was a difference in the infection rates, so just picking from the people who got infected would have completely distorted the results. But they would have arranged the study such that both people in the matched pair were considered for exactly the same time period. E.g. if the vaccinated person in pair was fully vaccinated on April 20th, they would have started counting re-infections for the previously infected person of the pair from April 20th too. Local infection rates should be the same, since the pairs would be matched from the same geographic area and the study contstruction ensured they were considered for exactly the same time period.
elcano 5y ago
So what is the public policy value of this study? We all should try to get Covid to get immunity to Covid? This is nonsense. This other study add some value: https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e1.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e1.htm It says that if you already got covid, the possibility of reinfection is 2.4 times lower if you also get the vaccine than if you don't get it. Now I guess that you multiply that natural immunity from 13x to 31x. Isn't cool?
kaminar 5y ago
Openvaers.com
Byte_01100110 5y ago
"yet to be peer reviewed " God damm it, journalists. Wait for that, this is what makes a study more credible that aunt Karens facebook posts
tim333 5y ago
The numbers here in the Israeli study seem very different from recent UK data which show pfizer and natural immunity being about the same. I'm not sure what accounts for the difference.

126 points by nostromo 5y ago

That's good news for people who have already recovered from Covid. We should definitely take that into account for policies around opening up again, i.e. by treating recovered people like vaccinated people. Beside that it is of little use, is it? "Get Covid to be better protected from Covid" doesn't make a lot of sense to me, at least.

nostromo 5y ago
People should obviously get vaccinated, yes. It does suggest that the vaccines could be improved to be even more effective. It’s also interesting that the people most resistant to delta are people that were both infected and vaccinated.
- lottin 5y ago
  I seem to recall someone suggested that since a large percentage of the population is vaccinated and are therefore protected against severe covid, we should now actually try to catch it to develop a natural immunity to the virus.
  - _Microft 5y ago
    I had skimmed and summarized such an article (submitted by someone else) a few weeks ago. I'm not sure that I would actually agree with it though. You can find it here: https://news.ycombinator.com/item?id=28109055 https://news.ycombinator.com/item?id=28109055
  - throwawaycities 5y ago
    The “problem” is that vaccinated people with the virus but experiencing no symptoms is that they still spread it to both unvaccinated and vaccinated alike. While many might not feel sympathy for the unvaccinated, a small % can’t get the vaccination, and there will still be that % of vaccinated people that do have a bad health outcome.
    - nradov 5y ago
      At this point the Delta variant is so contagious that there will be no significant herd immunity effect to protect unvaccinated individuals. They're going to get exposed and infected eventually no matter what we do. https://www.businessinsider.com/delta-variant-made-herd-immunity-not-possible-astrazeneca-developer-2021-8 https://www.businessinsider.com/delta-variant-made-herd-immu...
      - deleted 5y ago
        [deleted]
      - mlyle 5y ago
        Maybe. I quibble with "no significant herd immunity." I'm in an area with a very high vaccination rate (>87% of those over age 12 having had at least one dose, >80% fully vaccinated). Our case counts are a fraction of the rest of the country. The country's rates would be expected to be 3x lower if we could simply extrapolate my locale's rates among vaccinated and unvaccinated people to those fractions of the population in the rest of the country. This seems to hold up in other high-vaccination regions, though obviously there are confounds. The phase delay and greatly decreased count even makes me speculate that my locale (which is still using some mitigations) may be operating in a regime of Rt < 1.0 right now, and all case chains (slowly) geometrically decay from outside introductions from travel, etc. And we expect immunity to improve further, from kids being vaccinated and from more unvaccinated people getting infected. Maybe this isn't true. But we seem, at the least, to be experiencing some benefit beyond the direct benefits for vaccinated individuals.
        nradov 5y ago
        Case counts are meaningless as they largely reflect the level of testing. In most places there's not enough random population testing going on to get accurate infection counts. In the US the CDC estimates that infections are about 4× officially counted "cases".
        mlyle 5y ago
  - pengaru 5y ago
    It's not a hare brained idea, and it's been presented in the msm recently like @ https://www.bbc.co.uk/news/health-58270098 https://www.bbc.co.uk/news/health-58270098
  - foogazi 5y ago
    > we should now actually try to catch it to develop a natural immunity to the virus. We should catch it to get immunity so we don’t catch it ? I don’t get your thinking here
trhway 5y ago
>Beside that it is of little use, is it? "Get Covid to be better protected from Covid" doesn't make a lot of sense to me, at least. "Get Covid to better protect others from Covid" - Stronger immunity results in less chances to get infected again and less viral spread when infected. Ie. given that existing vaccines don't protect much against infection by delta, and that once infected the vaccinated spread the virus like unvaccinated, one can see that the people with natural immunity are much more preferable to have around than vaccinated.
- teachrdan 5y ago
  >once infected the vaccinated spread the virus like unvaccinated You are spreading disinformation. Vaccinated people who do get sick are less likely to spread the virus, and have a high viral load in their system for a shorter duration: --- A vaccinated person may have the same viral loads as an unvaccinated person, but that high level of virus lasts only three to four days compared with an unvaccinated person who could be contagious for up to 10 days, said Suresh Mittal, professor of virology at Purdue University’s College of Veterinary Medicine. “Individuals who are vaccinated have a good immune response. If they get in contact with people who are infected, they might get infected, but the majority may not transmit,” he said. https://www.usatoday.com/story/news/health/2021/08/11/covid-transmission-among-vaccinated-unvaccinated-what-experts-say/5488398001/ https://www.usatoday.com/story/news/health/2021/08/11/covid-...
  - trhway 5y ago
    >Vaccinated people who do get sick are less likely to spread the virus https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v1 https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v... "We find no difference in viral loads when comparing unvaccinated individuals to those who have vaccine “breakthrough” infections. " >that high level of virus lasts only three to four days compared with an unvaccinated person who could be contagious for up to 10 days may be. Yet it is the first days what matter until one notices that s/he is ill. And the article you cite has gems like this >Cases of breakthrough infections among the vaccinated remain rare. Where is for example in MA - with 65% vaccination rate - out of the 1400 new daily infections the 400+ are breakthrough : https://www.nbcboston.com/news/coronavirus/mass-has-3098-new-breakthrough-cases-7-more-covid-deaths-among-vaccinated/2475214/ https://www.nbcboston.com/news/coronavirus/mass-has-3098-new... And there is similar data from highly vaccinated places like UK, Israel, Singapore.
Gibbon1 5y ago
Well you have two options. Either 1) You force everyone to get tested for Covid. Then vaccinate everyone who tests negative. 2) Or you just vaccinate everyone knowing those that had it will just end up with stronger immunity. Seems like 2 is the cheapest most straightforward option.
- nradov 5y ago
  Those aren't the only options. It would be unethical to force testing on everyone.
  - Gibbon1 5y ago
    You can't trust people to self report having covid. Because a very high percentage will lie about it. Same as rules that allow vaccinated people to not wear masks. Unvaccinate people will up and lie about being vaccinated.
  - bserge 5y ago
    It's unethical to withhold mental health medication, too, but strangely no one gives a fuck about that.
  - retrac 5y ago
    We don't need to. People could be given the option of testing, or of going into isolation for the incubation period. Several countries had great effect from ordering a lockdown and testing the entire population over a day or two, releasing those who are negative from lockdown, and repeating this process multiple times in badly affected areas. Slovakia did this and it seems to have been extremely effective, though obviously not enough to eradicate it: https://www.bmj.com/content/371/bmj.m4761 https://www.bmj.com/content/371/bmj.m4761
    - nradov 5y ago
      Irrelevant. What appeared to work temporarily in Slovakia last year has no bearing on management of the more contagious Delta variant. Community transmission in most countries is so widespread now that there's simply no practical way to isolate so many people. It's just too late for that to work.
H8crilA 5y ago
Wait, which country isn't treating the recovered like the vaccinated? I thought it's standard, at least in Europe.
- aqme28 5y ago
  I know for my flight from the US to Europe, I need proof of vaccination. Proof "of immunity" is not sufficient.
  - H8crilA 5y ago
    Weird. I guess it's different for non citizens. https://ec.europa.eu/info/live-work-travel-eu/coronavirus-response/safe-covid-19-vaccines-europeans/eu-digital-covid-certificate_en https://ec.europa.eu/info/live-work-travel-eu/coronavirus-re...
- nostromo 5y ago
  That’s not the case in the US.
- dogma1138 5y ago
  In Europe you can get a certification only if you had a positive PCR result in the past 180 days. So if you want to travel right now freely you need to be double dosed unless you have recovered recently.
marlo111 5y ago
I've had COVID multiple times since this all started, no symptoms, I have positive tests and Antibodies. The pressure of getting the vaccine finally got to me. I didn't want to get it. Coming from a science background, my understanding is that my body is neutralizing COVID before it can cause any clinically expressed inflammation. The media, politics, and big pharma need to stay out of medicine, but it's too late.

deleted 5y ago

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phenkdo 5y ago

Isn't this literally survivorship bias?

tomesch1982 5y ago
That was also my first thought.
deleted 5y ago
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defaulty 5y ago
Sure, but for someone who has already /survived/, it's worth knowing the value of those antibodies. And it's worth knowing that governments should not attack those survivors further for "not getting vaccinated" when they already have antibodies. Worth noting that I'm not anti-vaccine but there's not enough focus on natural immunity. And I'm not encouraging people to forego vaccines and to go lick doorhandles
- johnchristopher 5y ago
  > And it's worth knowing that governments should not attack those survivors further for "not getting vaccinated" when they already have antibodies. Does delta change that ? Is natural immunity from a previous variant as effective against delta ?
  - JumpCrisscross 5y ago
    > Is natural immunity from a previous variant as effective against delta? This study's data come from during Israel's Delta-variant surge, so yes.
haroldship 5y ago
1) possibly, but in Israel nearly all deaths are over 60 but most infections are not so maybe not so much 2) depends on the question: if you ask if you should get vaccinated or get covid, then yes. If you ask whether it’s as safe to be around a recovered as a vaccinated, then not really

nostromo 5y ago

Preprint (awaiting peer review) study: https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...

tomesch1982 5y ago

Sounds a bit like survivor bias. People who have already recovered once (and not died) are more likely to recover a second time (and not die). In the control group, people who have never had the virus, some have a harder time with it. I hope this gets taken into account.

iab 5y ago
Exactly - “for those who didn’t die”
tim333 5y ago
Thankfully quite a small percentage of covid patients die. Certainly not enough for a 16x difference.
- MatteoFrigo 5y ago
  You cannot conclude anything about the 16x difference (TFA says 13x, by the way) from the number of dead patients. As a made up example to illustrate this point, assume that people are either "lucky" or "unlucky". Unlucky people die when they get the virus. Lucky people never die. Assume that one person per million is unlucky, and assume that the vaccine does absolutely nothing. Then this experiment on one million people would find one death in the vaccinated and zero deaths in the control group, inferring that natural immunity is infinitely better.
- CharlesW 5y ago
  Why do you believe "a small percentage of COVID-19 patients die" (which is only true compared to, say, Ebola) has any relevance to the results of this study?
  - tim333 5y ago
    The argument I was replying to is the numbers are skewed by survivorship bias, but given >98% of people survive that's only going to skew the numbers 2% or so not 600% or whatever.
- 5y ago

blueyes 5y ago

Does this mean that the ideal path for maximum immunity is to get vaccinated and then get a breakthrough infection?

ianlevesque 5y ago
Yes, which is basically how this ends 5 years from now. We’re probably all going to get exposed, but get your vaccine first!
- deleted 5y ago
  [deleted]
ardit33 5y ago
Yeah, Unless you are one of the unlucky ones... The fact it is that the virus will be around with us for a while, and everyone will probably get it at some point. Vaccination will help when dealing with it.
johnchristopher 5y ago
This should be compared to a third boost of a different vaccine.
hurlathroway 5y ago
It sounds like that might be our endgame now. If covid becomes endemic, which may be inevitable, then the only question is whether you want your body to be prepared for its first infection or not. I wonder if this could end up like the 'common cold' coronaviruses, where future generations build up immunity through exposure very early in life, resulting in mild infections in adulthood. That would beg an interesting question: how lethal would 'common colds' be if we hadn't all been exposed to them multiple times throughout our childhoods?
- dataflow 5y ago
  > 'common cold' coronaviruses I think you mean rhinoviruses?

criticaltinker 5y ago

This pre-print study has been discussed a few times on HN recently [1][2]. Many people are commenting that this paper is flawed by survivorship bias. While it would be useful to know the "cumulative" risk of SARS-CoV-2 infection, the fact is that a vast majority of people survive initial infection. So it is also useful to know the pure risk associated with reinfection - to inform public health policy and vaccine research. That is why the purpose of this research is to evaluate the risk of reinfection by directly comparing the effectiveness of natural immunity and vaccine-induced immunity in the context of the delta variant, which has mutations that confer partial immune escape. This research is significant because it is one of the first and largest studies to do so. [1] https://news.ycombinator.com/item?id=28327482 https://news.ycombinator.com/item?id=28327482 (350 comments) [2] https://news.ycombinator.com/item?id=28317866 https://news.ycombinator.com/item?id=28317866 (226 comments)

dredmorbius 5y ago

Natural immunity comes with a 10--25x greater risk of death, possibly much higher (see update) by COVID itself. (The risk from the vaccine, without a Covid infection, is effectively nil based on hundreds of millions of doses administered.) Natural immunity comes with a ~9x greater risk of hospitalisation, again from Covid itself. There's effectively no risk from the vaccine, again with hundreds of millions of doses administered. Among adults aged 65–74 years, effectiveness of full vaccination for preventing hospitalization was 96% for Pfizer-BioNTech, 96% for Moderna, and 84% for Janssen COVID-19 vaccines; among adults aged ≥75 years, effectiveness of full vaccination for preventing hospitalization was 91% for Pfizer-BioNTech, 96% for Moderna, and 85% for Janssen COVID-19 vaccines. https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e3.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e3.htm Note that "natural herd immunity" doesn't come without a near-total population infection rate, with a large number of deaths, prolonged medical care, and long-term health consequences. The vaccine-based risks are far, far, far lower. There's also quite likely a much higher likelihood of long-term Covid symptoms or consequences. This information is interesting, but a poor basis on which to shift policy from vaccination to infecting the entire population and blessing the survivors. Update: the article is also a dupe of an earlier substantial discussion: https://news.ycombinator.com/item?id=28307224 https://news.ycombinator.com/item?id=28307224 (260 comments). US CDC reports an 0.0016% fatality rate from all causes for vaccinated individuals. That's 100x lower than the incident fatality rate of 0.1% suggested by multiple countries with excellent Covid surveillance and reporting systems. Note that many early vaccine recipients were elderly (65+) and would have a higher natural death rate than the general population. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/adverse-events.html https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/ad... I've clarified the vaccine vs. natural infection risks based on criticism of unclear language.

didibus 5y ago
It's good as a combination I think. You can get the vaccine to prevent major illness and death, and if you catch Covid as a breakthrough case, you'd be even more strongly immune thereafter, hypothetically.
cwalv 5y ago
How does it compare to natural immunity from a "breakthrough infection"? If risk of hospitalization is low and following immunity is stronger, that seems relevant to whether we some should get booster shots, esp when so many haven't been able to get their first round

bigcorp-slave 5y ago

Non-peer reviewed study being flogged by the right wing to push an anti-vaccine agenda, upvoted on Hacker News. How is today unlike any other day? Yawn. Worse, the guy who’s posting this has been spreading COVID misinformation on this site for literally years.

deleted 5y ago
[deleted]

daenz 5y ago

Is there a difference in the immunity provided? What I mean is, does natural immunity do better at suppressing the transmission of covid19 than vaccine immunity? If that is the case, wouldn't that be an argument for encouraging every low-risk healthy person to develop natural immunity to suppress the spread to immunocompromised people?

dataflow 5y ago

Important note: this is for the delta variant. Vaccines appear to be less effective* against delta in general, and previous comparisons (like those that said vaccines are more effective [1]) were regarding earlier variants. I have yet to see anything that confirms that the conclusions of the study would be similar for other variants. (If you have any links supporting that, please do share.) [1] https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... * But still pretty darn effective. To be abundantly clear: this was in no way meant to suggest that it's a good idea to avoid getting vaccinated...

pplante 5y ago
Less effective at preventing infection, no less effective in preventing death or hospitalizations. We need to get everyone vaccinated to avoid the crush on our healthcare systems. Hospitals are facing bed shortages because many have given up on basic precautions in the USA.

user764743 5y ago

The data was posted as a preprint article on medRxiv, and hasn’t yet been reviewed by other researchers. Would take it with a grain of salt.

dredmorbius 5y ago

Note that this is a syndicated article from The Federalist a political opinion outlet, not a medical journal. The submitted link is from "ThinkCivics", a partisan news aggregator. The source is https://thefederalist.com/2021/08/27/israeli-study-natural-immunity-is-13x-stronger-than-pfizer-covid-shots/ https://thefederalist.com/2021/08/27/israeli-study-natural-i... Both sources are highly partisan and not especially given to an unbiased and facts-based interpretation or presentation of issues.

muttantt 5y ago

I know this is a controversial take, but it should be in our national interest to get young children exposed and gain natural immunity, and avoid giving them the vaccine we have so little long-term data on. According to the CDC, 450 kids (0-18yo) died from Covid-19 since Jan 2020. A total of 4.6M kids tested positive since then. In the much shorter 2017-2018 Flu season, ~650 kids (0-17) died. We really have to keep things in perspective.

bluedevil2k 5y ago
We don’t have any long term data on Covid infection either. Why risk children’s lives?
- muttantt 5y ago
  Because the vaccine is a risk factor on its own as well. Do you not agree with that?
  - JumpCrisscross 5y ago
    > vaccine is a risk factor on its own as well We have evidence, in adults, of long-term effects from Covid. These effects aren't benign, either, e.g. permanent damage to the brain's grey matter. We have zero evidence of long-term side effects from the vaccine. Ceteris paribus, infection is riskier than vaccines to adults. (I can think of zero diseases for which the vaccines are fine for adults and harmful to children and whose infections are harmful for adults and fine for children.) This study is compelling evidence for creating an analog to the vaccine passport for the provably previously infected. It is not good evidence for intentional infection.
  - bluedevil2k 5y ago
    No, not at all, if you understand how the vaccine works you wouldn’t either.
  - lamontcg 5y ago
    The vaccine risk is strictly a subset of the viral risk. Getting the virus entails getting a lot more of the spike mRNA pumping out a lot more spike protein along with all the rest of the viral machinery and real infectious virions, infecting more cells than just in the muscle of your arm, attacking your heart, lungs, kidneys, etc. Getting the virus is always going to be worse, for everyone, than getting the vaccine. Which is also why people refusing to get the vaccine because they've been infected is dumb, because they already beat everything in the vaccine.

forty 5y ago

I'm curious, couldn't we just get a shot of virus after the 2 Pfizer shots to benefit from this stronger immunity?

andy_ppp 5y ago

Is there any case for offering people a dose of COVID-19 at the peak of their vaccine immunity and scheduled when people can self isolate? It just seems we’re all going to get a variant of COVID at some point before it becomes like another flu that occurs yearly?

viburnum 5y ago

What if you get vaccinated and then get a breakthrough infection? How's your immunity then?

didibus 5y ago
From what I've seen, this is where we seem to have lucked out. In that if you get Covid as a vaccinated person, it will still dramatically reduce your chances of being hospitalized or dying from it. > August 25, 2021 — The Health Department today released new data on vaccine effectiveness and breakthrough cases, hospitalizations and deaths. Between January 17 and August 7, 2021, 96.1% of COVID-19 cases, 96.9% of COVID-19 hospitalizations, and 97.3% of COVID-19 deaths in New York City were in people who were unvaccinated or not fully vaccinated. Additionally, for the same time period, 0.33% of fully vaccinated New Yorkers have ever been diagnosed with COVID-19, 0.02% have been hospitalized with COVID-19, and 0.003% have died due to complications with COVID-19. > from August 7, unvaccinated New Yorkers are 3.1 times more likely to get COVID-19 than fully vaccinated New Yorkers. Additionally, unvaccinated New Yorkers are almost 10 times more likely to be hospitalized with COVID-19 than those who are fully vaccinated You can read more here: https://www1.nyc.gov/site/doh/about/press/pr2021/health-department-releases-data-covid-19-vaccine-effectiveness.page https://www1.nyc.gov/site/doh/about/press/pr2021/health-depa...

sergiotapia 5y ago

If you're young and not fat, why would you get the vaccine? Just lose weight and exercise. If you're a child, why would your parents want you to get vaccinated if there's no risk at all? I hope these studies are conclusive once and for all.

bserge 5y ago
I agree if you sign a waiver saying you get no healthcare in the rare case that your infection requires hospitalization. That's my stance on prescription medication, too, in case you think I'm just being an asshole about CV. I'd sign a waiver for the freedom to buy antidepressants.

throwaway5752 5y ago

I want to ask about source material for a minute. What is ThinkCivics? Why is it reasonable second-hand source for analysis of a non-peer reviewed article? Does it have editorial biases? I am asking sincerely. It is a new site to me, and I don't know if it is a trustworthy source of information. The site is also unresponsive at the time I'm writing this.

yehosef 5y ago
Anything that questions the value of vaccines should be suspected as misinformation, regardless of the source.
- fileeditview 5y ago
  Is that sarcasm?
  - yehosef 5y ago
    No, unfortunately.
zaik 5y ago
The text is copied from a website called "The Federalist": https://en.m.wikipedia.org/wiki/The_Federalist_(website) https://en.m.wikipedia.org/wiki/The_Federalist_(website)
- throwaway5752 5y ago
  It's plagiarized?
  - zaik 5y ago
    No, the original source is stated at the bottom of the text. The website seems to be a news areggator with a focus on US conservative talking points.
anigbrowl 5y ago

joelbondurant 5y ago

This must be taken down, all Science must be ordained by the USA Fact-Check Algorithm of the Science Ministry. Communists unite in diaper face unity!

bserge 5y ago

Yeah, whatever. How long does immunity last? I had Covid in February, kinda curious if I still have the antibodies. But I'm not paying 80 Euros to find out, unless you crowdfund me :D

nradov 5y ago
There's more to immunity than antibodies. Even if you don't have detectible levels of antibodies your memory T cells may be providing some protection. Many blood donation centers conduct free antibody tests for donors so you might want to check if that's an option.

rgbrenner 5y ago

can we change the URL to the paper?[0] The "article" is just blog spam consisting of a few quotes from the abstract of the paper. And I had to go find a cached version because the site was down. 0. https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v1 https://www.medrxiv.org/content/10.1101/2021.08.24.21262415v...

jsnell 5y ago
The paper was also discussed on HN three days ago (245 comments): https://news.ycombinator.com/item?id=28307224 https://news.ycombinator.com/item?id=28307224

joelbondurant 5y ago

Driving through Rocky Mountain National Park is 45 times more lethal than staying home, so I'm wearing a mask to protect my shadow.

m3kw9 5y ago

But first you would need to get infected to acquire such immunity. Pretty much defeats the purpose when it could cause severe outcomes which you wanted to avoid in the first place. But rather, even though you may get the infected after vaccination, it will lower the chance of severe outcome by nearly as much. I’d rather acquire natural immunity via the vaccine route.

anigbrowl 5y ago

By the famed medical experts at the Federalist ◔_◔ I think for an assertion like this it's better to link directly to the study preprint rather than a tendentious summary of it.

fastaguy88 5y ago

Some of the numbers in the tables seem strange to me. Looking at the participants, it is hard to understand how the mean and sd of the ages and age distributions can be exactly the same. Moreover, apparently the odds of being hospitalized are 160-times greater for vaccinated vs unvaccinated second infection individuals. Perhaps the dramatic differences are due to very low numbers - I did not see the raw numbers for symptomatic infection and hospitalization. But if I were reviewing this paper, I would wonder how they got their age distributions to match so closely.

jsnell 5y ago
It's a matched cohort study. They're starting with a large population in both of their target groups, and then picking pairs of demographically identical people (e.g. age, sex, location), one from each group, for the study. So you'd certainly expect the age distributions to match up exactly. It'd be more worrying if criteria they weren't doing the matching by also were exactly identical. That's not the case, all kinds of secondary characteristics such as comorbidities are roughly but not exactly the same.
- fastaguy88 5y ago
  Thanks. One wonders how closely they matched time of infection and local infection rate.
  - jsnell 5y ago
    They couldn't have matched the time of infection, since not everyone in the study was (re-)infected during the study period. The point of the study was to see if there was a difference in the infection rates, so just picking from the people who got infected would have completely distorted the results. But they would have arranged the study such that both people in the matched pair were considered for exactly the same time period. E.g. if the vaccinated person in pair was fully vaccinated on April 20th, they would have started counting re-infections for the previously infected person of the pair from April 20th too. Local infection rates should be the same, since the pairs would be matched from the same geographic area and the study contstruction ensured they were considered for exactly the same time period.

elcano 5y ago

So what is the public policy value of this study? We all should try to get Covid to get immunity to Covid? This is nonsense. This other study add some value: https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e1.htm https://www.cdc.gov/mmwr/volumes/70/wr/mm7032e1.htm It says that if you already got covid, the possibility of reinfection is 2.4 times lower if you also get the vaccine than if you don't get it. Now I guess that you multiply that natural immunity from 13x to 31x. Isn't cool?

kaminar 5y ago

Openvaers.com

Byte_01100110 5y ago

"yet to be peer reviewed " God damm it, journalists. Wait for that, this is what makes a study more credible that aunt Karens facebook posts

tim333 5y ago

The numbers here in the Israeli study seem very different from recent UK data which show pfizer and natural immunity being about the same. I'm not sure what accounts for the difference.