5 ms·

Does anyone know how the 66% effectiveness of the vacine compares to people who were exposed to COVID but never got the vaccine?

smt88 5y ago
It doesn't matter in countries like the US where the vaccine is free to anyone who wants it. We know the vaccine improves survival regardless of previous infections. https://www.uchicagomedicine.org/forefront/coronavirus-disease-covid-19/do-i-need-a-vaccine-if-i-had-covid https://www.uchicagomedicine.org/forefront/coronavirus-disea... It's a little bit like mixing and matching vaccines to get better protection (which some countries are forced to do because they don't have access to the best single vaccine).
- AndrewBissell 5y ago
  Nothing in your link supports the claim "we know the vaccine improves survival regardless of previous infections." > It doesn't matter in countries like the US where the vaccine is free to anyone who wants it How about the medical bills for a life-altering adverse event? Are those free for anyone who has to pay them? These considerations matter when we're talking about administering a vaccine which may provide very slim or no additional protection over natural immunity. There has already been one study suggesting the second dose of Pfizer even reduces cellular and humoral immune response.
  - zht 5y ago
    oh sorry how many of those life altering adverse events have there been as a percentage of people vaccinated?
    - AndrewBissell 5y ago
      How many extremely bad disease outcomes have there been as a percentage of all Covid reinfections?
  - bananabiscuit 5y ago
    There’s a CDC study that shows vaccinating while previously infected, further boosts your immunity by more than double https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... What they don’t mention is that previous infection alone is at least as good as vaccination alone. According to data from Israel, previous infection is about 6x more effective in fact. https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... Given that, I don’t at all agree with the conclusion of that CDC study that you HAVE to get vaccinated if you had a previous infection.
    - AndrewBissell 5y ago
      What that study shows is that unvaccinated people in the study cohort were twice as likely to experience a reinfection. A lot of things could explain that and it's a far cry from establishing that it boosts immunity. The study period was also during the point when effectiveness of the initial mRNA vaccine doses was probably peaking.
  - triceratops 5y ago
    > How about the medical bills for a life-altering adverse event? Like when you get seriously ill with Covid and have to be hospitalized in the ICU? That's more likely than an adverse reaction to a vaccine, if we're assuming that everyone will get Covid at some point.
    - AndrewBissell 5y ago
      We're specifically discussing people with immunity from having recovered from a prior Covid infection, in whom serious life-altering illness from a reinfection is also extraordinarily rare.
      - triceratops 5y ago
        > in whom serious life-altering illness from a reinfection is also extraordinarily rare. Only as far as we're talking about reinfections from currently known variants. We've seen that current vaccines are still pretty good against Delta despite not being tailored to it. Is it not possible for vaccines to provide immunity against a future variant that's much deadlier upon reinfection?
  - zeku 5y ago
    Link the study or delete your comment.
    - AndrewBissell 5y ago
      Here you go. Wonder what a third dose will do! https://www.biorxiv.org/content/10.1101/2021.03.22.436441v1 https://www.biorxiv.org/content/10.1101/2021.03.22.436441v1
criticaltinker 5y ago
Immunity acquired through natural infection confers protection that is at least as effective as vaccination [1]. However, the delta variant and other VOCs have mutations that will reduce this protection in both vaccinated and naturally immune individuals. > A previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. This time period is the minimum probable effect because seroconversions were not included. This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals. [1] [1] SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN) https://pubmed.ncbi.nlm.nih.gov/33844963/ https://pubmed.ncbi.nlm.nih.gov/33844963/
hattmall 5y ago
Reinfection rate is less than 1%. The biggest issue is that there were lots of false positives with certain tests if you had Flu or other coronavirus colds even if asymptomatic. Even current antibody testing can't distinguish COVID-19 from other coronavirus based colds. If you had asymptomatic or low symptoms and positive test there's a fair chance you didn't really have COVID. If you had symptoms with shortness of breath and loss of smell without heavy congestion you probably did have COVID.

smt88 5y ago

It doesn't matter in countries like the US where the vaccine is free to anyone who wants it. We know the vaccine improves survival regardless of previous infections. https://www.uchicagomedicine.org/forefront/coronavirus-disease-covid-19/do-i-need-a-vaccine-if-i-had-covid https://www.uchicagomedicine.org/forefront/coronavirus-disea... It's a little bit like mixing and matching vaccines to get better protection (which some countries are forced to do because they don't have access to the best single vaccine).

AndrewBissell 5y ago
Nothing in your link supports the claim "we know the vaccine improves survival regardless of previous infections." > It doesn't matter in countries like the US where the vaccine is free to anyone who wants it How about the medical bills for a life-altering adverse event? Are those free for anyone who has to pay them? These considerations matter when we're talking about administering a vaccine which may provide very slim or no additional protection over natural immunity. There has already been one study suggesting the second dose of Pfizer even reduces cellular and humoral immune response.
- zht 5y ago
  oh sorry how many of those life altering adverse events have there been as a percentage of people vaccinated?
  - AndrewBissell 5y ago
    How many extremely bad disease outcomes have there been as a percentage of all Covid reinfections?
- bananabiscuit 5y ago
  There’s a CDC study that shows vaccinating while previously infected, further boosts your immunity by more than double https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... What they don’t mention is that previous infection alone is at least as good as vaccination alone. According to data from Israel, previous infection is about 6x more effective in fact. https://www.cdc.gov/media/releases/2021/s0806-vaccination-protection.html https://www.cdc.gov/media/releases/2021/s0806-vaccination-pr... Given that, I don’t at all agree with the conclusion of that CDC study that you HAVE to get vaccinated if you had a previous infection.
  - AndrewBissell 5y ago
    What that study shows is that unvaccinated people in the study cohort were twice as likely to experience a reinfection. A lot of things could explain that and it's a far cry from establishing that it boosts immunity. The study period was also during the point when effectiveness of the initial mRNA vaccine doses was probably peaking.
- triceratops 5y ago
  > How about the medical bills for a life-altering adverse event? Like when you get seriously ill with Covid and have to be hospitalized in the ICU? That's more likely than an adverse reaction to a vaccine, if we're assuming that everyone will get Covid at some point.
  - AndrewBissell 5y ago
    We're specifically discussing people with immunity from having recovered from a prior Covid infection, in whom serious life-altering illness from a reinfection is also extraordinarily rare.
    - triceratops 5y ago
      > in whom serious life-altering illness from a reinfection is also extraordinarily rare. Only as far as we're talking about reinfections from currently known variants. We've seen that current vaccines are still pretty good against Delta despite not being tailored to it. Is it not possible for vaccines to provide immunity against a future variant that's much deadlier upon reinfection?
- zeku 5y ago
  Link the study or delete your comment.
  - AndrewBissell 5y ago
    Here you go. Wonder what a third dose will do! https://www.biorxiv.org/content/10.1101/2021.03.22.436441v1 https://www.biorxiv.org/content/10.1101/2021.03.22.436441v1

criticaltinker 5y ago

Immunity acquired through natural infection confers protection that is at least as effective as vaccination [1]. However, the delta variant and other VOCs have mutations that will reduce this protection in both vaccinated and naturally immune individuals. > A previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. This time period is the minimum probable effect because seroconversions were not included. This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals. [1] [1] SARS-CoV-2 infection rates of antibody-positive compared with antibody-negative health-care workers in England: a large, multicentre, prospective cohort study (SIREN) https://pubmed.ncbi.nlm.nih.gov/33844963/ https://pubmed.ncbi.nlm.nih.gov/33844963/

hattmall 5y ago

Reinfection rate is less than 1%. The biggest issue is that there were lots of false positives with certain tests if you had Flu or other coronavirus colds even if asymptomatic. Even current antibody testing can't distinguish COVID-19 from other coronavirus based colds. If you had asymptomatic or low symptoms and positive test there's a fair chance you didn't really have COVID. If you had symptoms with shortness of breath and loss of smell without heavy congestion you probably did have COVID.