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In this thread, none of the comments seem to note a key issue here as stated in the FDA post: "Those participants who did not receive two vaccine doses at eithe

In this thread, none of the comments seem to note a key issue here as stated in the FDA post: "Those participants who did not receive two vaccine doses at either a three-or four-week interval were generally only followed for a short period of time, such that we cannot conclude anything definitive about the depth or duration of protection after a single dose of vaccine from the single dose percentages reported by the companies. " In other words, we basically have NO DATA on single dose schedules for Moderna/Pfizer vaccines. There's too few of them anyway to gain any statistically meaningful insight even if we did follow up on these study participant washouts. This is hydroxychloroquine all over again. When you are looking at inadequate data, you can find all sorts of patterns. It is very rare that such patterns turn out to be real. The most reasonable approach is to assume that there is little to no durable protection from a single dose, just like most prime/boost vaccines.

dcolkitt 6y ago
> The most reasonable approach is to assume that there is little to no durable protection from a single dose How is that the most reasonable approach? Virtually every vaccine ever discovered provides more immunity on first dose, than the incremental gain on subsequent boosters. You certainly can't be sure of this, but pre-existing evidence would strongly suggest that this vaccine is subject to the law of diminishing returns. At the end of the day, we're just trying to maximize infections prevented. If the two-dose schedule confers 95% immunity, then as long as we expect over 50% immunity from a single dose, then First Dose First is best policy.
- s0rce 6y ago
  Propose to the companies to conduct a trial to test your hypothesis on the effectiveness of a single dose? Until then the FDA policy is clearly data based and they are saying to follow the tested dose schedule from the clinical trial and not to deviate.
  - dcolkitt 6y ago
    Hypothetical question. Imagine if for some reason everyone in the trial received the vaccine on a rainy day (maybe it occured in Seattle during a bad patch of weather). The vaccine shows immunity, but we can only be sure for a population that got it on a rainy day. Now we're distributing the vaccine, but the bottleneck is that we have to keep waiting for rainy days. It's especially bad in Arizona and Nevada. Is your contention that we keep the rainy day requirement? Even when all are scientific and empirical priors tell us that the effect is de minims. The example is kind of silly, but it makes my point. There's literally countless number of factors that go into any trial. There's no possible way that the way treatment is deployed in the field will exactly match the way it was tested. Yet doctors, scientists and public health experts use judgement and empirical priors to determine when and where we can relax the requirements.
    - s0rce 6y ago
      I think the analogy to your example is to have conducted a larger trial where the dose was given under different weather conditions, or in the case of the real vaccine vary the timing of the 2nd dose. I agree, if experts agree the likelihood that 1 dose is effective and the likelihood of it being ineffective is low, we should do what will save the most lives. This is an emergency.
      - hcknwscommenter 6y ago
        " if experts agree the likelihood that 1 dose is effective and the likelihood of it being ineffective is low" Experts do not agree.
    - abduhl 6y ago
      > Yet doctors, scientists and public health experts use judgement and empirical priors to determine when and where we can relax the requirements. They certainly do. And the FDA, a collection of the leading doctors, scientists, and public health experts, just told you that two doses is the regimen. Is there something that you know that these experts don't?
- panda-giddiness 6y ago
  > How is that the most reasonable approach? The reasonable approach is to be overly cautious. A false sense of security is worse than no security at all.
  - nl 6y ago
    > A false sense of security is worse than no security at all. True. But that isn't what is happening here. This is more "some level of security which is less than absolute, and unclear what sense of security people will assume they have" We've seen "false sense of security" arguments used time and time again to oppose partial, imperfect safety interventions (seat belts in cars is a great example).
  - dhnajsjdnd 6y ago
    The cautious thing to do is vaccinate the entire population with two doses. Oops, we don’t have enough doses for that.
  - esoterica 6y ago
    Letting a couple hundred thousand people die because of a slow vaccination schedule is NOT the cautious approach.
- rpedela 6y ago
  We have no data for mRNA vaccines except those trials. We don't know if the historical data on traditional vaccines are applicable here. As such, it is also possible that a single dose isn't good enough or a single dose is good enough but only for a couple months. We just don't know and it would be way worse if it turns out we have to re-vaccinate everyone because we were impatient.
  - esoterica 6y ago
    > We have no data for mRNA vaccines except those trials. We don't know if the historical data on traditional vaccines are applicable here. This is not how decision making under uncertainty works. When you don't have rigorous proof of whether something works or doesn't work you have to make educated guesses based on various priors and make the percentage play. You can't refuse to incorporate priors into your decision making just because you don't have a peer reviewed p<0.05 study validating it. Uncertainty about the result cuts both ways. You can't claim that we can't do X over Y because we don't have rigorous proof that X is better than Y, when we don't have rigorous proof that Y is better than X either. Regardless of what you do you're taking a leap of faith. > We just don't know and it would be way worse if it turns out we have to re-vaccinate everyone because we were impatient. If there's probability p that it doesn't work and we have to spend X extra months re-vaccinating everyone that's an expected delay of p * X. But if it does work then not pursuing the single dose strategy will delay the vaccination schedule by X' months also. If p * X < (1-p) * X' then the former is a perfectly acceptable risk.
    - rpedela 6y ago
      I personally try to make decisions using probability. I understand where you are coming from but there is one factor missing in your analysis: this situation is literally life and death. That changes the math a bit to something more akin to "better safe than sorry" in my opinion. We have found a guaranteed path out of this mess. There may be other faster paths that save more lives, but it could also end up killing millions more too. I'm all for experimenting but I take issue with making the experiment the policy when lives are on the line.
  - 6y ago
- jzwinck 6y ago
  It's not only about minimizing total infections. If it were, priority would be given based on social sphere sizes, eg priests and postmen before old people. It's also about giving people a vaccine they can believe in, which allows them to return to some of their normal activities. If everyone is 50% safe, no one has any real expectation that they can take any risks without being infected. If half the people are 95% safe, that half can do more things (travel long distances, go to school) while the unvacccinated half can continue to avoid risks until more vaccine is available.
  - owl57 6y ago
    > It's not only about minimizing total infections. If it were, priority would be given based on social sphere sizes, eg priests and postmen before old people. Exactly how it is rolled out here in Moscow. It has never occurred to me that it's not the one and obvious way. But yes, the "Sputnik" vaccine has huge problems with giving people something they can believe in. Rolling it out in a "rational" order, as if they actually believe it works, is probably the most city government can do to raise confidence.
- hcknwscommenter 6y ago
  "Virtually every vaccine ever discovered provides more immunity on first dose, than the incremental gain on subsequent boosters." Citation needed.
- anderskaseorg 6y ago
  It’s not just a question of 95% immunity vs. 50% immunity (even if we were to take your arbitrary 50% number at face value). It’s also a question of how long we expect the immunity to last for two-dose vs. one-dose, and where we expect to be in terms of virus spread and vaccine manufacturing and vaccination rates when that initial immunity runs out. These are complicated questions.
feralimal 6y ago
we have also not had animal trials - there is very little data at all. We will get that in 2 years, once the live trials are completed.
- paxswill 6y ago
  There were animal trials. Here's an overview post of various vaccine's primate trials: https://blogs.sciencemag.org/pipeline/archives/2020/07/30/coronavirus-challenges-in-primates-compared https://blogs.sciencemag.org/pipeline/archives/2020/07/30/co... And as linked in that post, Moderna's primate study: https://www.nejm.org/doi/full/10.1056/NEJMoa2024671?query=featured_home https://www.nejm.org/doi/full/10.1056/NEJMoa2024671?query=fe...
cltby 6y ago
It's simply pathological to claim that we have NO DATA just because a large scale RCT wasn't performed. For starters, we have profound differences in the attack curves between treatment and control group, starting about 14 days after administration of the first dose [1]. I don't have the numbers in front of me, but I'm going to guess the trial size is more than adequately powered to detect differences 27 days out. All this is exactly as theory would predict. Seroconversion typically takes about two weeks. Once seroconversion happens, immunity lasts years (if not decades), which is why most booster doses are given years apart [2]. And any talk of "full efficacy" is confusing population statistics with individual outcomes. To say that Moderna is ~85% effective after one dose, as it appears to be, is to say that 85% of the population will produce antibodies after a single dose. There is no "partial immunity"--you're immune or you're not. [1] https://www.ft.com/content/7cebed90-3267-4651-a249-56f5a9ae7684 https://www.ft.com/content/7cebed90-3267-4651-a249-56f5a9ae7... [2] https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolesc...
- jschwartzi 6y ago
  We have data, but no information. We have to synthesize the data into information using analytical techniques or it is meaningless.
- nl 6y ago
  Note that this isn't a "booster shot" in the sense of the boosters you are linking. These are rDNA Prime/Boost vaccines, which is completely different to the conventional vaccines with the multi-year booster regime. I agree that the 14 and 27 day attack curves should provide some efficiency data though.
  - cltby 6y ago
    Your cells will take up the mRNA and manufacture spike protein, which is the antigen of interest. We should expect this to be pretty similar to just injecting the antigen directly, as the other vaccines do.
- jfengel 6y ago
mikem170 6y ago
> we basically have NO DATA on single dose schedules for Moderna/Pfizer vaccines I wonder if anything can be deduced given knowledge of the mechanisms these vaccines use compared to other vaccines against other viruses. I know there are vaccines like for HEP-A that confer immunity for at least 10 years given a single shot, and a 20+ years of immunity if a booster is given in six months. It appears that the FDA doesn't want to offer any information outside of the studies. This cut in half the number of people who can be protected during this winter's covid season.
mchusma 6y ago
"No data" is wildly incorrect. We have priors from other vaccines and vaccine candidates, and the data from these trials. All data about the first dose suggests strongly that 1 dose provides very strong protection against severe disease, and solid protection against mild disease. Most vaccines have increased efficacy when spreading out the doses, so the same is likely true here, which means this is most likely to increase efficacy. We don't have data on lots of things, like what if we vaccinated people in cars instead of indoors? We can't run RCTs for everything in this world. People are also not advocating for 1 dose only, rather spreading the doses out more to get more people vaccinated faster. 1 dose first, followed by another 12 weeks later is almost certainly going to be highly effective and it's almost certainly going to be safe. This is also not a binary decision. To let you to 10M people try this regime while watching the data has as close to "only upside" as you can get in medicine. If the FDA approved Astrazeneca now, and the states focused on getting first doses, we could be done with this pandemic in like 45 days. It's worth taking a tiny amount of risk that this group of 10M might not have effective immunity and need to be revaccinated.
- credit_guy 6y ago
  Wholeheartedly agree with this. EUA means Emergency Use Authorization. Emergency, yes, that's what Covid is. As such, leadership means taking some calculated risks. What FDA essentially does is "you can't get fired for buying IBM". They stick to "we don't have any data for this and that", "this is what the science shows", and people out there are dying. A perfect demonstration of lack of leadership.
- murgindrag 6y ago
  It does provide protection, but what we don't know is: 1) For how long 2) How it impacts future vaccination efforts (As well as a slew of other things) If it was just #1, I'd be with you. If we give a big chunk of the population a vaccine which lasts 6 months and makes them unimmunizable, we've changed a serious problem into a serious, serious problem.
  - zaroth 6y ago
    > ...and makes them unimmunizable... Is there any scientific basis for this hypothetical?
excerionsforte 6y ago
Agreed. Taking a conservative approach to something you don't yet understand is the best approach on a mass scale. There isn't any significant data for the one dose approach. These vaccines are only authorized on an EUA on a specific way to apply the dosage and it would be foolhardly to experiment now with different approaches on health care workers who are high risk on the front line. Definitely need more data on the single dose approach and if that proves safe enough then providers can go that route. Playing with people's health because we want to go cowboy and extract many doses as possible is irresponsible. What happens if the single dose approach doesn't work as well as hoped? I wouldn't want to be that guinea pig who thought "I'm protected". How long will it be that all hospitals get the information to go back to the two dose approach. Consistent messaging is key during this pandemic. That alone has been hard enough.
- Animats 6y ago
  Yes. At this phase, it's best to stick to what's known to work. Besides, right now most countries are having more problems getting immunizations done than getting vaccine supplies. Broward County, FL just put vaccinations on Eventbrite, as a fast way to get appointments set up.[1] [1] https://www.theverge.com/2021/1/4/22213307/covid-vaccine-florida-eventbrite https://www.theverge.com/2021/1/4/22213307/covid-vaccine-flo...
- propogandist 6y ago
  >What happens if the single dose approach doesn't work as well as hoped? "240 Israelis found with COVID after vaccination, underscoring need for vigilance" https://www.timesofisrael.com/240-israelis-diagnosed-after-vaccination-underscore-need-for-continued-vigilance/ https://www.timesofisrael.com/240-israelis-diagnosed-after-v...
  - makomk 6y ago
    This will happen under any dosing schedule, because we already know the vaccine doesn't become effective until some time after the first dose. (Which is also one of the reasons it's hard to tell exactly how much benefit the second dose gives.)
esoterica 6y ago
"NO DATA" is an epistemologically bankrupt cop-out. We don't have RCTs that prove that jumping out of an airplane with a parachute is safer than jumping out of a plane without one. And yet everyone packs a chute when jumping out of a plane. Why is that so? Because we have priors based on our understanding of physics and biology that hitting the ground slowly is less likely to kill you than hitting the ground fast. The same is true for vaccines; we have lots of them and we can make an educated guesses about how new ones work, even if new vaccines may not always behave the same as old ones. When you have to make decisions under uncertainty you can't refuse to incorporate educated guesses just because you don't have rigorous p<0.05 peer-reviewed proof confirming those hypotheses.
jdkee 6y ago
My wife’s hospital in the US has had their 2nd round delayed by 4-5 days so the 21 day interval is off. We shall see.

dcolkitt 6y ago

> The most reasonable approach is to assume that there is little to no durable protection from a single dose How is that the most reasonable approach? Virtually every vaccine ever discovered provides more immunity on first dose, than the incremental gain on subsequent boosters. You certainly can't be sure of this, but pre-existing evidence would strongly suggest that this vaccine is subject to the law of diminishing returns. At the end of the day, we're just trying to maximize infections prevented. If the two-dose schedule confers 95% immunity, then as long as we expect over 50% immunity from a single dose, then First Dose First is best policy.

s0rce 6y ago
Propose to the companies to conduct a trial to test your hypothesis on the effectiveness of a single dose? Until then the FDA policy is clearly data based and they are saying to follow the tested dose schedule from the clinical trial and not to deviate.
- dcolkitt 6y ago
  Hypothetical question. Imagine if for some reason everyone in the trial received the vaccine on a rainy day (maybe it occured in Seattle during a bad patch of weather). The vaccine shows immunity, but we can only be sure for a population that got it on a rainy day. Now we're distributing the vaccine, but the bottleneck is that we have to keep waiting for rainy days. It's especially bad in Arizona and Nevada. Is your contention that we keep the rainy day requirement? Even when all are scientific and empirical priors tell us that the effect is de minims. The example is kind of silly, but it makes my point. There's literally countless number of factors that go into any trial. There's no possible way that the way treatment is deployed in the field will exactly match the way it was tested. Yet doctors, scientists and public health experts use judgement and empirical priors to determine when and where we can relax the requirements.
  - s0rce 6y ago
    I think the analogy to your example is to have conducted a larger trial where the dose was given under different weather conditions, or in the case of the real vaccine vary the timing of the 2nd dose. I agree, if experts agree the likelihood that 1 dose is effective and the likelihood of it being ineffective is low, we should do what will save the most lives. This is an emergency.
    - hcknwscommenter 6y ago
      " if experts agree the likelihood that 1 dose is effective and the likelihood of it being ineffective is low" Experts do not agree.
  - abduhl 6y ago
    > Yet doctors, scientists and public health experts use judgement and empirical priors to determine when and where we can relax the requirements. They certainly do. And the FDA, a collection of the leading doctors, scientists, and public health experts, just told you that two doses is the regimen. Is there something that you know that these experts don't?
panda-giddiness 6y ago
> How is that the most reasonable approach? The reasonable approach is to be overly cautious. A false sense of security is worse than no security at all.
- nl 6y ago
  > A false sense of security is worse than no security at all. True. But that isn't what is happening here. This is more "some level of security which is less than absolute, and unclear what sense of security people will assume they have" We've seen "false sense of security" arguments used time and time again to oppose partial, imperfect safety interventions (seat belts in cars is a great example).
- dhnajsjdnd 6y ago
  The cautious thing to do is vaccinate the entire population with two doses. Oops, we don’t have enough doses for that.
- esoterica 6y ago
  Letting a couple hundred thousand people die because of a slow vaccination schedule is NOT the cautious approach.
rpedela 6y ago
We have no data for mRNA vaccines except those trials. We don't know if the historical data on traditional vaccines are applicable here. As such, it is also possible that a single dose isn't good enough or a single dose is good enough but only for a couple months. We just don't know and it would be way worse if it turns out we have to re-vaccinate everyone because we were impatient.
- esoterica 6y ago
  > We have no data for mRNA vaccines except those trials. We don't know if the historical data on traditional vaccines are applicable here. This is not how decision making under uncertainty works. When you don't have rigorous proof of whether something works or doesn't work you have to make educated guesses based on various priors and make the percentage play. You can't refuse to incorporate priors into your decision making just because you don't have a peer reviewed p<0.05 study validating it. Uncertainty about the result cuts both ways. You can't claim that we can't do X over Y because we don't have rigorous proof that X is better than Y, when we don't have rigorous proof that Y is better than X either. Regardless of what you do you're taking a leap of faith. > We just don't know and it would be way worse if it turns out we have to re-vaccinate everyone because we were impatient. If there's probability p that it doesn't work and we have to spend X extra months re-vaccinating everyone that's an expected delay of p * X. But if it does work then not pursuing the single dose strategy will delay the vaccination schedule by X' months also. If p * X < (1-p) * X' then the former is a perfectly acceptable risk.
  - rpedela 6y ago
    I personally try to make decisions using probability. I understand where you are coming from but there is one factor missing in your analysis: this situation is literally life and death. That changes the math a bit to something more akin to "better safe than sorry" in my opinion. We have found a guaranteed path out of this mess. There may be other faster paths that save more lives, but it could also end up killing millions more too. I'm all for experimenting but I take issue with making the experiment the policy when lives are on the line.
- 6y ago
jzwinck 6y ago
It's not only about minimizing total infections. If it were, priority would be given based on social sphere sizes, eg priests and postmen before old people. It's also about giving people a vaccine they can believe in, which allows them to return to some of their normal activities. If everyone is 50% safe, no one has any real expectation that they can take any risks without being infected. If half the people are 95% safe, that half can do more things (travel long distances, go to school) while the unvacccinated half can continue to avoid risks until more vaccine is available.
- owl57 6y ago
  > It's not only about minimizing total infections. If it were, priority would be given based on social sphere sizes, eg priests and postmen before old people. Exactly how it is rolled out here in Moscow. It has never occurred to me that it's not the one and obvious way. But yes, the "Sputnik" vaccine has huge problems with giving people something they can believe in. Rolling it out in a "rational" order, as if they actually believe it works, is probably the most city government can do to raise confidence.
hcknwscommenter 6y ago
"Virtually every vaccine ever discovered provides more immunity on first dose, than the incremental gain on subsequent boosters." Citation needed.
anderskaseorg 6y ago
It’s not just a question of 95% immunity vs. 50% immunity (even if we were to take your arbitrary 50% number at face value). It’s also a question of how long we expect the immunity to last for two-dose vs. one-dose, and where we expect to be in terms of virus spread and vaccine manufacturing and vaccination rates when that initial immunity runs out. These are complicated questions.

feralimal 6y ago

we have also not had animal trials - there is very little data at all. We will get that in 2 years, once the live trials are completed.

paxswill 6y ago
There were animal trials. Here's an overview post of various vaccine's primate trials: https://blogs.sciencemag.org/pipeline/archives/2020/07/30/coronavirus-challenges-in-primates-compared https://blogs.sciencemag.org/pipeline/archives/2020/07/30/co... And as linked in that post, Moderna's primate study: https://www.nejm.org/doi/full/10.1056/NEJMoa2024671?query=featured_home https://www.nejm.org/doi/full/10.1056/NEJMoa2024671?query=fe...

cltby 6y ago

It's simply pathological to claim that we have NO DATA just because a large scale RCT wasn't performed. For starters, we have profound differences in the attack curves between treatment and control group, starting about 14 days after administration of the first dose [1]. I don't have the numbers in front of me, but I'm going to guess the trial size is more than adequately powered to detect differences 27 days out. All this is exactly as theory would predict. Seroconversion typically takes about two weeks. Once seroconversion happens, immunity lasts years (if not decades), which is why most booster doses are given years apart [2]. And any talk of "full efficacy" is confusing population statistics with individual outcomes. To say that Moderna is ~85% effective after one dose, as it appears to be, is to say that 85% of the population will produce antibodies after a single dose. There is no "partial immunity"--you're immune or you're not. [1] https://www.ft.com/content/7cebed90-3267-4651-a249-56f5a9ae7684 https://www.ft.com/content/7cebed90-3267-4651-a249-56f5a9ae7... [2] https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolesc...

jschwartzi 6y ago
We have data, but no information. We have to synthesize the data into information using analytical techniques or it is meaningless.
nl 6y ago
Note that this isn't a "booster shot" in the sense of the boosters you are linking. These are rDNA Prime/Boost vaccines, which is completely different to the conventional vaccines with the multi-year booster regime. I agree that the 14 and 27 day attack curves should provide some efficiency data though.
- cltby 6y ago
  Your cells will take up the mRNA and manufacture spike protein, which is the antigen of interest. We should expect this to be pretty similar to just injecting the antigen directly, as the other vaccines do.
jfengel 6y ago

mikem170 6y ago

> we basically have NO DATA on single dose schedules for Moderna/Pfizer vaccines I wonder if anything can be deduced given knowledge of the mechanisms these vaccines use compared to other vaccines against other viruses. I know there are vaccines like for HEP-A that confer immunity for at least 10 years given a single shot, and a 20+ years of immunity if a booster is given in six months. It appears that the FDA doesn't want to offer any information outside of the studies. This cut in half the number of people who can be protected during this winter's covid season.

mchusma 6y ago

"No data" is wildly incorrect. We have priors from other vaccines and vaccine candidates, and the data from these trials. All data about the first dose suggests strongly that 1 dose provides very strong protection against severe disease, and solid protection against mild disease. Most vaccines have increased efficacy when spreading out the doses, so the same is likely true here, which means this is most likely to increase efficacy. We don't have data on lots of things, like what if we vaccinated people in cars instead of indoors? We can't run RCTs for everything in this world. People are also not advocating for 1 dose only, rather spreading the doses out more to get more people vaccinated faster. 1 dose first, followed by another 12 weeks later is almost certainly going to be highly effective and it's almost certainly going to be safe. This is also not a binary decision. To let you to 10M people try this regime while watching the data has as close to "only upside" as you can get in medicine. If the FDA approved Astrazeneca now, and the states focused on getting first doses, we could be done with this pandemic in like 45 days. It's worth taking a tiny amount of risk that this group of 10M might not have effective immunity and need to be revaccinated.

credit_guy 6y ago
Wholeheartedly agree with this. EUA means Emergency Use Authorization. Emergency, yes, that's what Covid is. As such, leadership means taking some calculated risks. What FDA essentially does is "you can't get fired for buying IBM". They stick to "we don't have any data for this and that", "this is what the science shows", and people out there are dying. A perfect demonstration of lack of leadership.
murgindrag 6y ago
It does provide protection, but what we don't know is: 1) For how long 2) How it impacts future vaccination efforts (As well as a slew of other things) If it was just #1, I'd be with you. If we give a big chunk of the population a vaccine which lasts 6 months and makes them unimmunizable, we've changed a serious problem into a serious, serious problem.
- zaroth 6y ago
  > ...and makes them unimmunizable... Is there any scientific basis for this hypothetical?

excerionsforte 6y ago

Agreed. Taking a conservative approach to something you don't yet understand is the best approach on a mass scale. There isn't any significant data for the one dose approach. These vaccines are only authorized on an EUA on a specific way to apply the dosage and it would be foolhardly to experiment now with different approaches on health care workers who are high risk on the front line. Definitely need more data on the single dose approach and if that proves safe enough then providers can go that route. Playing with people's health because we want to go cowboy and extract many doses as possible is irresponsible. What happens if the single dose approach doesn't work as well as hoped? I wouldn't want to be that guinea pig who thought "I'm protected". How long will it be that all hospitals get the information to go back to the two dose approach. Consistent messaging is key during this pandemic. That alone has been hard enough.

Animats 6y ago
Yes. At this phase, it's best to stick to what's known to work. Besides, right now most countries are having more problems getting immunizations done than getting vaccine supplies. Broward County, FL just put vaccinations on Eventbrite, as a fast way to get appointments set up.[1] [1] https://www.theverge.com/2021/1/4/22213307/covid-vaccine-florida-eventbrite https://www.theverge.com/2021/1/4/22213307/covid-vaccine-flo...
propogandist 6y ago
>What happens if the single dose approach doesn't work as well as hoped? "240 Israelis found with COVID after vaccination, underscoring need for vigilance" https://www.timesofisrael.com/240-israelis-diagnosed-after-vaccination-underscore-need-for-continued-vigilance/ https://www.timesofisrael.com/240-israelis-diagnosed-after-v...
- makomk 6y ago
  This will happen under any dosing schedule, because we already know the vaccine doesn't become effective until some time after the first dose. (Which is also one of the reasons it's hard to tell exactly how much benefit the second dose gives.)

esoterica 6y ago

"NO DATA" is an epistemologically bankrupt cop-out. We don't have RCTs that prove that jumping out of an airplane with a parachute is safer than jumping out of a plane without one. And yet everyone packs a chute when jumping out of a plane. Why is that so? Because we have priors based on our understanding of physics and biology that hitting the ground slowly is less likely to kill you than hitting the ground fast. The same is true for vaccines; we have lots of them and we can make an educated guesses about how new ones work, even if new vaccines may not always behave the same as old ones. When you have to make decisions under uncertainty you can't refuse to incorporate educated guesses just because you don't have rigorous p<0.05 peer-reviewed proof confirming those hypotheses.

jdkee 6y ago

My wife’s hospital in the US has had their 2nd round delayed by 4-5 days so the 21 day interval is off. We shall see.