21 ms·

Considering all the excluded groups on the trial (page 3, kids, 55+, obese, weak immune system, a lot more), it's a lot of exclusions, how does one get from res

by fcsp 6y ago

Considering all the excluded groups on the trial (page 3, kids, 55+, obese, weak immune system, a lot more), it's a lot of exclusions, how does one get from results on a study like this to declaring the vaccine safe for general use?

bun_at_work 6y ago
Not really qualified to answer this, but I would imagine follow-on rounds of testing. Also, those groups should be protected through herd immunity if everyone else gets the vaccine.
refurb 6y ago
Extrapolation. Is there a scientific rationale as to why the vaccine would NOT be safe and effective in a new population? If not, approve it for that population. If there is rationale why it wouldn’t be, ask for more data.
- bosie 6y ago
  Why would the reasons used to exclude those cohorts in the first place not be used to determine the vaccine is unsafe for said cohorts?
  - refurb 6y ago
    Noise in the data and ethics. Noise in the data - you want as clean a population as you can get. If you start including people with chronic conditions, as soon as someone in your trial dies you get to play a game called "prove that it wasn't the vaccine that killed them". Same with people over 55 years old - they are known to respond differently to vaccines. The worst thing in the world would be showing a 49.4% reduction in Covid infection rate (the FDA wants 50% minimum) and then being forced to do a bunch of handwaving about how your results were skewed by the 55+ patients in your study and "by gosh, I swear it would be over 50% if we adjust for them using this methodology we just made up". Nobody will believe you and you'll be relegated to "that vaccine that almost works". Ethics - Kids aren't (well, very rarely) dying from Covid, but they could die after getting your experimental vaccine. Kids sickened by experimental drugs makes for bad press, not only you, but also the FDA. Easier to just exclude them for now.
- deleted 6y ago
  [deleted]
thebruce87m 6y ago
Maybe a stupid question, but do we need to vaccinate everyone? I remember reading that heard immunity is 70% or something - so could we get away with leaving the people out that it wasn’t tested on?
- moultano 6y ago
  The vaccine may itself not be perfectly protective, and the herd immunity threshold only works if the people vaccinated are random. Otherwise any unvaccinated population can have an outbreak.
- 24gttghh 6y ago
  https://en.wikipedia.org/wiki/Herd_immunity#Mechanics https://en.wikipedia.org/wiki/Herd_immunity#Mechanics It varies by disease. Can anyone really say what the % is/would be for covid-19?
  - hsitz 6y ago
    You should be able to see that Covid-19 is in fact a disease listed in the table on the wikipedia page you reference. You should also be able to see that the percentage required for herd immunity effect to begin (the 'herd immunity threshold') is a function of the R0 level for each disease. In addition, to question of "can anyone really say for covid-19", I suppose the answer is 'No, but I would trust that the consensus of the scientific community of infectious disease experts is the best estimation we can get.'
    - 24gttghh 6y ago
      It was just a wikipedia table, and the citations actually referred to SARS, not COVID... Hence my skepticism.
- SamBam 6y ago
  It's not a stupid question, and I've heard that some vaccines are aiming to be approved only for adults at first. This would make sense not only because, as you say, you can start to approach herd immunity without vaccinating everyone, but also because children are weaker spreaders. Obviously "herd immunity" is more of a gradient than a cut-off, and it's much easier to approach it if we can vaccinate everyone, but we can definitely speed up the process (including the months-long process to even get the vaccines to everyone) if we can start vaccinating some people early.
nate510 6y ago
Generally speaking, experimental drug trials are run first on healthy groups and then in at-risk groups (old, young, those with co-morbidities). From the article, my guess is that they are expediting the sensitive groups trials, but unfortunately there's a lack of technical detail. Source: My partner is an infectious disease specialist and we talk about this pretty much daily because I'm so curious.
- ponker 6y ago
  But for this disease that's particularly bad because Covid has shown to be worst in 55+, obese, comorbidities, etc... which means that the trials on healthy groups are proving very little, since the virus itself is so much weaker on healthy groups.
  - EpicEng 6y ago
    >But for this disease that's particularly bad because... Doesn't change the fact that, when you're developing a new drug, you want to test it in a way which will cause the least harm. You don't begin trials with those most at risk for obvious reasons. The primary goal of this phase it to asses the safety of the vaccine candidate. I'm also unaware of any disease that isn't more threatening to people in relatively poor health.
    - cookingrobot 6y ago
      You say it’s “obvious” but it’s the opposite of my intuition. Can you explain the logic a bit more? I would have thought you’d give a risky new drug to the least healthy, most likely to die without it population, to raise the chance of survival from low to unknown.
      - bentcorner 6y ago
        Later on you'd want to give the determined-to-be-safe new drug to the least healthy (if possible), or those that come in close contact to them. At this stage they still need to ensure the drug is safe, so they test it on healthy people first.
SN76477 6y ago
"The purpose of this study is to text a new vaccine against COVID-19 in healthy volunteers. So I am assuming this is the control group.
- ska 6y ago
  The control group will not be given the vaccine, but a placebo. Clinical trials are phased. Typically you start with a very small group of people to evaluate toxicity (e.g. below treatment levels of a drug), then a slightly larger group looking for side effect, then a significantly larger group looking for desired effects, and finally a broad group looking for safety and efficacy.
- BurningFrog 6y ago
  This is a combined phase 1/2 trial. It tests that the vaccine doesn't hurt or kill people too much, and that it has some immune system effect. After that a phase 3 study is done on tens of thousands of people from all possible demographics.
  - mathw 6y ago
    That phase 3 study for the Oxford vaccine is already underway, and its initial findings are what the article is referring to. It was one of the first (possibly the first, I'm not entirely sure) to enter phase 3.
0898 6y ago
Why would tabloid glamour models be excluded?
- GekkePrutser 6y ago
  Vaccines often cause a minor cosmetic bump. If you see people with a triangle of bumps on their shoulder for example they have received a common vaccine for healthcare workers. And the smallpox one can leave an even bigger scar. I suppose they don't want the liability for that which could impact the model's income
  - LandR 6y ago
    Tabloid glamour models obviously aren't excluded, the posters joke was a reference to this > excluded groups on the trial (page 3,
    - GekkePrutser 6y ago
      Ahh ok! :D Now that you mention it I had heard of the British Page 3 tradition but it didn't occur to me at the time.
Bobblebobble 6y ago
This phase I/II study's primary objective was to learn about the safety of the vaccine, and about whether it causes an immune response. I'm no expert, but I expect the phase III trials in the US and India will include a broader population.
- fcsp 6y ago
  Ah, thanks for clarifying that you participated in phase 1/2, I had not gotten this from skimming through the document, that makes a lot more sense to me. Thanks for sharing!
  - BurningFrog 6y ago
    It is mentioned up top, but I had to search for it.
FuckButtons 6y ago
There isn’t just one trial - there are other safety trials being run in vulnerable groups.
rightnow 6y ago
If the majority gets a vaccin and gets immune the virus dies out. Then there is no need for a vaccin for the rest

by fcsp 6y ago

bun_at_work 6y ago

Not really qualified to answer this, but I would imagine follow-on rounds of testing. Also, those groups should be protected through herd immunity if everyone else gets the vaccine.

refurb 6y ago

Extrapolation. Is there a scientific rationale as to why the vaccine would NOT be safe and effective in a new population? If not, approve it for that population. If there is rationale why it wouldn’t be, ask for more data.

bosie 6y ago
Why would the reasons used to exclude those cohorts in the first place not be used to determine the vaccine is unsafe for said cohorts?
- refurb 6y ago
  Noise in the data and ethics. Noise in the data - you want as clean a population as you can get. If you start including people with chronic conditions, as soon as someone in your trial dies you get to play a game called "prove that it wasn't the vaccine that killed them". Same with people over 55 years old - they are known to respond differently to vaccines. The worst thing in the world would be showing a 49.4% reduction in Covid infection rate (the FDA wants 50% minimum) and then being forced to do a bunch of handwaving about how your results were skewed by the 55+ patients in your study and "by gosh, I swear it would be over 50% if we adjust for them using this methodology we just made up". Nobody will believe you and you'll be relegated to "that vaccine that almost works". Ethics - Kids aren't (well, very rarely) dying from Covid, but they could die after getting your experimental vaccine. Kids sickened by experimental drugs makes for bad press, not only you, but also the FDA. Easier to just exclude them for now.
deleted 6y ago
[deleted]

thebruce87m 6y ago

Maybe a stupid question, but do we need to vaccinate everyone? I remember reading that heard immunity is 70% or something - so could we get away with leaving the people out that it wasn’t tested on?

moultano 6y ago
The vaccine may itself not be perfectly protective, and the herd immunity threshold only works if the people vaccinated are random. Otherwise any unvaccinated population can have an outbreak.
24gttghh 6y ago
https://en.wikipedia.org/wiki/Herd_immunity#Mechanics https://en.wikipedia.org/wiki/Herd_immunity#Mechanics It varies by disease. Can anyone really say what the % is/would be for covid-19?
- hsitz 6y ago
  You should be able to see that Covid-19 is in fact a disease listed in the table on the wikipedia page you reference. You should also be able to see that the percentage required for herd immunity effect to begin (the 'herd immunity threshold') is a function of the R0 level for each disease. In addition, to question of "can anyone really say for covid-19", I suppose the answer is 'No, but I would trust that the consensus of the scientific community of infectious disease experts is the best estimation we can get.'
  - 24gttghh 6y ago
    It was just a wikipedia table, and the citations actually referred to SARS, not COVID... Hence my skepticism.
SamBam 6y ago
It's not a stupid question, and I've heard that some vaccines are aiming to be approved only for adults at first. This would make sense not only because, as you say, you can start to approach herd immunity without vaccinating everyone, but also because children are weaker spreaders. Obviously "herd immunity" is more of a gradient than a cut-off, and it's much easier to approach it if we can vaccinate everyone, but we can definitely speed up the process (including the months-long process to even get the vaccines to everyone) if we can start vaccinating some people early.

nate510 6y ago

Generally speaking, experimental drug trials are run first on healthy groups and then in at-risk groups (old, young, those with co-morbidities). From the article, my guess is that they are expediting the sensitive groups trials, but unfortunately there's a lack of technical detail. Source: My partner is an infectious disease specialist and we talk about this pretty much daily because I'm so curious.

ponker 6y ago
But for this disease that's particularly bad because Covid has shown to be worst in 55+, obese, comorbidities, etc... which means that the trials on healthy groups are proving very little, since the virus itself is so much weaker on healthy groups.
- EpicEng 6y ago
  >But for this disease that's particularly bad because... Doesn't change the fact that, when you're developing a new drug, you want to test it in a way which will cause the least harm. You don't begin trials with those most at risk for obvious reasons. The primary goal of this phase it to asses the safety of the vaccine candidate. I'm also unaware of any disease that isn't more threatening to people in relatively poor health.
  - cookingrobot 6y ago
    You say it’s “obvious” but it’s the opposite of my intuition. Can you explain the logic a bit more? I would have thought you’d give a risky new drug to the least healthy, most likely to die without it population, to raise the chance of survival from low to unknown.
    - bentcorner 6y ago
      Later on you'd want to give the determined-to-be-safe new drug to the least healthy (if possible), or those that come in close contact to them. At this stage they still need to ensure the drug is safe, so they test it on healthy people first.

SN76477 6y ago

"The purpose of this study is to text a new vaccine against COVID-19 in healthy volunteers. So I am assuming this is the control group.

ska 6y ago
The control group will not be given the vaccine, but a placebo. Clinical trials are phased. Typically you start with a very small group of people to evaluate toxicity (e.g. below treatment levels of a drug), then a slightly larger group looking for side effect, then a significantly larger group looking for desired effects, and finally a broad group looking for safety and efficacy.
BurningFrog 6y ago
This is a combined phase 1/2 trial. It tests that the vaccine doesn't hurt or kill people too much, and that it has some immune system effect. After that a phase 3 study is done on tens of thousands of people from all possible demographics.
- mathw 6y ago
  That phase 3 study for the Oxford vaccine is already underway, and its initial findings are what the article is referring to. It was one of the first (possibly the first, I'm not entirely sure) to enter phase 3.

0898 6y ago

Why would tabloid glamour models be excluded?

GekkePrutser 6y ago
Vaccines often cause a minor cosmetic bump. If you see people with a triangle of bumps on their shoulder for example they have received a common vaccine for healthcare workers. And the smallpox one can leave an even bigger scar. I suppose they don't want the liability for that which could impact the model's income
- LandR 6y ago
  Tabloid glamour models obviously aren't excluded, the posters joke was a reference to this > excluded groups on the trial (page 3,
  - GekkePrutser 6y ago
    Ahh ok! :D Now that you mention it I had heard of the British Page 3 tradition but it didn't occur to me at the time.

Bobblebobble 6y ago

This phase I/II study's primary objective was to learn about the safety of the vaccine, and about whether it causes an immune response. I'm no expert, but I expect the phase III trials in the US and India will include a broader population.

fcsp 6y ago
Ah, thanks for clarifying that you participated in phase 1/2, I had not gotten this from skimming through the document, that makes a lot more sense to me. Thanks for sharing!
- BurningFrog 6y ago
  It is mentioned up top, but I had to search for it.

FuckButtons 6y ago

There isn’t just one trial - there are other safety trials being run in vulnerable groups.

rightnow 6y ago

If the majority gets a vaccin and gets immune the virus dies out. Then there is no need for a vaccin for the rest