7 ms·

Number of unvaccinated people needed to exclude to prevent 1 Covid transmission

24 points by busymom0 5y ago

raxxorrax 5y ago
I somehow doubt this will have an political impact. Science gets ignored if you can make easy statements for the masses that see not vaccinated people as the enemy. It gives them a sense of control and security. I think this would also make any mandate pretty much superfluous if you disregard personal security.
mint2 5y ago
Too bad Covid moves so fast that the papers are already outdated. Interesting methodology but the actual number conclusion is heavily dependent on case rates so the top line number conclusions are rather out dated until cases come down drastically.
- busymom0 5y ago
  The author did an interview here where he addressed that too. Basically with Omicron and waning effectiveness, the NNE raises even higher: https://youtu.be/wAI4GSzTYTU https://youtu.be/wAI4GSzTYTU
busymom0 5y ago
This calculates the NNE which is similar to NNT: The Number Needed to Treat (NNT) is the number of patients you need to treat to prevent one additional bad outcome (death, stroke, etc.). For example, if a drug has an NNT of 5, it means you have to treat 5 people with the drug to prevent one additional bad outcome. As a general rule of thumb, an NNT of 5 or under for treating a symptomatic condition is usually considered to be acceptable and in some cases even NNTs below 10. https://www.uws.edu/wp-content/uploads/2013/10/Number_Needed_to_Treat.pdf https://www.uws.edu/wp-content/uploads/2013/10/Number_Needed...
- d0mine 5y ago
  There are drugs that are taken by millions with NNT in ~100s e.g., statin.
  - busymom0 5y ago
    You are missing the point. This NNE is regarding whether mandating vaccine passport at gyms, restaurants has any benefit to reducing transmission.
    - d0mine 5y ago
      I said nothing about NNE. My comment is point out that NNT <10 is too optimistic
- joshuamorton 5y ago
  I'm so confused by the math here, since the same authors in another paper find that the NNV (number needed to vaccinate) to prevent a transmission is less than 20, but the number needed to exclude is 100x higher. My guess is that you can look at this over a time period: how many places do you go into in a (week/month/year) that you could not if you were unvaccinated. People can be vaccinated, but can be excluded many times. How many people are excluded by a single restaurant per week? At higher prevalence rates, this translates to like an infection prevented per restaurant per day or higher, and at lower rates, its a few per month.
  - liamwestray 5y ago
    Time periods kinda messes up these analyses because statistics is hard for a lot of people. "Second, while risk over time is important, people are primarily concerned about the risk of getting infected with SARS- CoV-2 right now, not, for example, over the last 3 months." The authors just kinda brush this aside. Their analyses are focused on singular events such as social gatherings, going to work, transportation, etc. Incase I'm not getting my point across, this is REALLY, REALLY STUPID, and I'd be embarrassed to publish this kind of analysis.. They also focus solely on the psychological harm of exclusion of unvaccinated people (very real consequences of serious mental and economic impacts to these people). Not actual harm of adverse reactions to the vaccines (effectively 0 actual harm), but make comparisons to drugs with considerably more side effects. Not considering cumulative effects of even a single week on transmissibility radically skews their analysis. We don't do this in health and safety when death is on the line for a reason... To put this another way, their analysis compares statins, a drug used to combat a constant exposure to heart-attack and stroke risk (from cholesterol), to a 1-8 hour singular event of exposure of unvaccinated people who may or may not have CoViD. No Doctor I know would prescribe statins if you only had risk of heart-attack or stroke for a 1-8 hour event on a single day.
    - busymom0 5y ago
      > effectively zero harm What? There’s multiple studies showing the risk of a young boy between 16-24 developing myocarditis is higher than their risk of getting hospitalized from Covid. And this myocarditis risk rises based on the interval between first and second dose, rises for each dose, is even higher for Moderna. Also for men under 40, the risks of developing myocarditis from the shots is higher than the risk of myocarditis from Covid. https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdf https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v... Is makes absolutely no sense to mandate the shots for any young person, especially if they are fit and healthy.
reindeer76 5y ago
Excluding unvaccinated people has nothing to do with preventing disease. Ever since the wide availability of effective vaccines last summer, the purpose of most Covid restrictions is to expand the surveillance state and compel obedience to the pharma-government alliance.
- codeddesign 5y ago
  Looks like you got downvoted by the HN mob for stating an unpopular opinion. To an extent I don’t disagree with you. The CDC’s recent changes were obviously forced on them to encourage more people to work or go out and spend.
- ipspam 5y ago
  I think most people can agree that it has nothing to do with preventing the disease, but there will be a smorgasbord of educated and uneducated guesses about the real purpose of vaccine passports. You might even say digital passports are just an evolution of humanity, the disease is irrelevant, and they will be repurposed afterwards. Say like to discourage bad behaviour (social credit score passport), passport passport (to control and track movement), carbon passport (to track individual emissions), internet passport (to prevent viewing of things deemed to lead to extremism), privilege and adversity passport (to compare victimhood and oppressor status and advance equity) Etc etc. I think my point is that all passports are bad for the individual, and if we accept passports, we will be stuck with a passport for every single social issue of the day. A permenant scorecard.
- errantmind 5y ago
  I agree that the end result is an expansion of the surveillance state. I don't think it is all that coordinated, just a bunch of miscellaneous opportunists, all following their own incentives, all converging on a common narrative.. a decentralized 'conversation' among people that stand to gain.
stathibus 5y ago
This is an extremely unintuitive result.
- icodestuff 5y ago
  I think it has something to do with when the data analyzed is from: the nadir of the delta wave, before omicron. They mention a low base transmission rate, which is very much no longer applicable, and say the results are applicable to China, Australia, Israel, and other countries (where the virus is/was largely suppressed). Its applicability to the US right now seems very limited at best.
  - busymom0 5y ago
    The author stated in an interview yesterday that with Omicron and waning effectiveness, the NNE raises even higher: https://youtu.be/wAI4GSzTYTU https://youtu.be/wAI4GSzTYTU The 1000 figure from his study is the lower bound.
  - roenxi 5y ago
    The vaccination status of Australia (~93% vaccinations 12+) suggest that vaccines don't do anything practical to slow the spread of omicron. It seems to be vaccinated individuals infecting vaccinated individuals. All the anti-anti-vax efforts seem to be a bit futile. It makes the current brouhaha over Djokovic is just silly - he's more at risk from Australians than Australians are for him. I'm double vaccinated and still probably going to get COVID in the next month and there isn't even going to be a good tennis match to watch while I'm coughing and sneezing. What is the justification of this sillyness now?
    - liamwestray 5y ago
      As of the latest data in the US for vaccinated people re: Omicron: You're 13x less likely to land in the hospital. You're 45x less likely to die. It's gone from being 10-20x more deadly than the flu to half as deadly with the vaccine. And Omicron hasn't peaked yet in the U.S., these numbers are likely conservative. Last I checked you had 1/14th the population and 1/30th the deaths we had. You got the vaccine later than we did, hit 93% vaccination rate while we're STILL below 65%. Australia took things way more seriously than we did, maybe a bit "too conservatively" for your taste, but the alternative I live in is that 2 aunt's funerals were over zoom (pre vaccine), and my I'm waiting for my 63 yr old uncle (anti-vax) who had a heart attack 3 years ago, is obese, been a lifelong smoker, and just got CoViD to recover.
mint2 5y ago
I’m not an expert on this so could someone explain how if secondary attack is defined like this google search gave me form another paper: >” Secondary attack rate (SAR) is the probability that an infection occurs among susceptible persons within a reasonable incubation period after known contact with an infectious person in household or other close-contact environments.” Explain how the nne calc doesn’t need to account for the number of people in the situation. Is there other better or more clear definitions? Or Should the base rate be adjusted to account for number of people? My other question is, is the NNE about unique excluded people or is it just unique excluded visits. I.e a single person is excluded from eating at a restaurant at lunch and then again at dinner, does that count for 2 of the 1000?
- liamwestray 5y ago
  The paper considers normalized/averaged single event exposure for their analysis and compares it to continuous exposure of other drugs and vaccines to make their case. It's embarrassingly flawed analysis.

24 points by busymom0 5y ago

I somehow doubt this will have an political impact. Science gets ignored if you can make easy statements for the masses that see not vaccinated people as the enemy. It gives them a sense of control and security. I think this would also make any mandate pretty much superfluous if you disregard personal security.

mint2 5y ago

Too bad Covid moves so fast that the papers are already outdated. Interesting methodology but the actual number conclusion is heavily dependent on case rates so the top line number conclusions are rather out dated until cases come down drastically.

busymom0 5y ago
The author did an interview here where he addressed that too. Basically with Omicron and waning effectiveness, the NNE raises even higher: https://youtu.be/wAI4GSzTYTU https://youtu.be/wAI4GSzTYTU

busymom0 5y ago

This calculates the NNE which is similar to NNT: The Number Needed to Treat (NNT) is the number of patients you need to treat to prevent one additional bad outcome (death, stroke, etc.). For example, if a drug has an NNT of 5, it means you have to treat 5 people with the drug to prevent one additional bad outcome. As a general rule of thumb, an NNT of 5 or under for treating a symptomatic condition is usually considered to be acceptable and in some cases even NNTs below 10. https://www.uws.edu/wp-content/uploads/2013/10/Number_Needed_to_Treat.pdf https://www.uws.edu/wp-content/uploads/2013/10/Number_Needed...

d0mine 5y ago
There are drugs that are taken by millions with NNT in ~100s e.g., statin.
- busymom0 5y ago
  You are missing the point. This NNE is regarding whether mandating vaccine passport at gyms, restaurants has any benefit to reducing transmission.
  - d0mine 5y ago
    I said nothing about NNE. My comment is point out that NNT <10 is too optimistic
joshuamorton 5y ago
I'm so confused by the math here, since the same authors in another paper find that the NNV (number needed to vaccinate) to prevent a transmission is less than 20, but the number needed to exclude is 100x higher. My guess is that you can look at this over a time period: how many places do you go into in a (week/month/year) that you could not if you were unvaccinated. People can be vaccinated, but can be excluded many times. How many people are excluded by a single restaurant per week? At higher prevalence rates, this translates to like an infection prevented per restaurant per day or higher, and at lower rates, its a few per month.
- liamwestray 5y ago
  Time periods kinda messes up these analyses because statistics is hard for a lot of people. "Second, while risk over time is important, people are primarily concerned about the risk of getting infected with SARS- CoV-2 right now, not, for example, over the last 3 months." The authors just kinda brush this aside. Their analyses are focused on singular events such as social gatherings, going to work, transportation, etc. Incase I'm not getting my point across, this is REALLY, REALLY STUPID, and I'd be embarrassed to publish this kind of analysis.. They also focus solely on the psychological harm of exclusion of unvaccinated people (very real consequences of serious mental and economic impacts to these people). Not actual harm of adverse reactions to the vaccines (effectively 0 actual harm), but make comparisons to drugs with considerably more side effects. Not considering cumulative effects of even a single week on transmissibility radically skews their analysis. We don't do this in health and safety when death is on the line for a reason... To put this another way, their analysis compares statins, a drug used to combat a constant exposure to heart-attack and stroke risk (from cholesterol), to a 1-8 hour singular event of exposure of unvaccinated people who may or may not have CoViD. No Doctor I know would prescribe statins if you only had risk of heart-attack or stroke for a 1-8 hour event on a single day.
  - busymom0 5y ago
    > effectively zero harm What? There’s multiple studies showing the risk of a young boy between 16-24 developing myocarditis is higher than their risk of getting hospitalized from Covid. And this myocarditis risk rises based on the interval between first and second dose, rises for each dose, is even higher for Moderna. Also for men under 40, the risks of developing myocarditis from the shots is higher than the risk of myocarditis from Covid. https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v1.full.pdf https://www.medrxiv.org/content/10.1101/2021.12.23.21268276v... Is makes absolutely no sense to mandate the shots for any young person, especially if they are fit and healthy.

reindeer76 5y ago

Excluding unvaccinated people has nothing to do with preventing disease. Ever since the wide availability of effective vaccines last summer, the purpose of most Covid restrictions is to expand the surveillance state and compel obedience to the pharma-government alliance.

codeddesign 5y ago
Looks like you got downvoted by the HN mob for stating an unpopular opinion. To an extent I don’t disagree with you. The CDC’s recent changes were obviously forced on them to encourage more people to work or go out and spend.
ipspam 5y ago
I think most people can agree that it has nothing to do with preventing the disease, but there will be a smorgasbord of educated and uneducated guesses about the real purpose of vaccine passports. You might even say digital passports are just an evolution of humanity, the disease is irrelevant, and they will be repurposed afterwards. Say like to discourage bad behaviour (social credit score passport), passport passport (to control and track movement), carbon passport (to track individual emissions), internet passport (to prevent viewing of things deemed to lead to extremism), privilege and adversity passport (to compare victimhood and oppressor status and advance equity) Etc etc. I think my point is that all passports are bad for the individual, and if we accept passports, we will be stuck with a passport for every single social issue of the day. A permenant scorecard.
errantmind 5y ago
I agree that the end result is an expansion of the surveillance state. I don't think it is all that coordinated, just a bunch of miscellaneous opportunists, all following their own incentives, all converging on a common narrative.. a decentralized 'conversation' among people that stand to gain.

stathibus 5y ago

This is an extremely unintuitive result.

icodestuff 5y ago
I think it has something to do with when the data analyzed is from: the nadir of the delta wave, before omicron. They mention a low base transmission rate, which is very much no longer applicable, and say the results are applicable to China, Australia, Israel, and other countries (where the virus is/was largely suppressed). Its applicability to the US right now seems very limited at best.
- busymom0 5y ago
  The author stated in an interview yesterday that with Omicron and waning effectiveness, the NNE raises even higher: https://youtu.be/wAI4GSzTYTU https://youtu.be/wAI4GSzTYTU The 1000 figure from his study is the lower bound.
- roenxi 5y ago
  The vaccination status of Australia (~93% vaccinations 12+) suggest that vaccines don't do anything practical to slow the spread of omicron. It seems to be vaccinated individuals infecting vaccinated individuals. All the anti-anti-vax efforts seem to be a bit futile. It makes the current brouhaha over Djokovic is just silly - he's more at risk from Australians than Australians are for him. I'm double vaccinated and still probably going to get COVID in the next month and there isn't even going to be a good tennis match to watch while I'm coughing and sneezing. What is the justification of this sillyness now?
  - liamwestray 5y ago
    As of the latest data in the US for vaccinated people re: Omicron: You're 13x less likely to land in the hospital. You're 45x less likely to die. It's gone from being 10-20x more deadly than the flu to half as deadly with the vaccine. And Omicron hasn't peaked yet in the U.S., these numbers are likely conservative. Last I checked you had 1/14th the population and 1/30th the deaths we had. You got the vaccine later than we did, hit 93% vaccination rate while we're STILL below 65%. Australia took things way more seriously than we did, maybe a bit "too conservatively" for your taste, but the alternative I live in is that 2 aunt's funerals were over zoom (pre vaccine), and my I'm waiting for my 63 yr old uncle (anti-vax) who had a heart attack 3 years ago, is obese, been a lifelong smoker, and just got CoViD to recover.

mint2 5y ago

I’m not an expert on this so could someone explain how if secondary attack is defined like this google search gave me form another paper: >” Secondary attack rate (SAR) is the probability that an infection occurs among susceptible persons within a reasonable incubation period after known contact with an infectious person in household or other close-contact environments.” Explain how the nne calc doesn’t need to account for the number of people in the situation. Is there other better or more clear definitions? Or Should the base rate be adjusted to account for number of people? My other question is, is the NNE about unique excluded people or is it just unique excluded visits. I.e a single person is excluded from eating at a restaurant at lunch and then again at dinner, does that count for 2 of the 1000?

liamwestray 5y ago
The paper considers normalized/averaged single event exposure for their analysis and compares it to continuous exposure of other drugs and vaccines to make their case. It's embarrassingly flawed analysis.