4 ms·

I heard somewhere that we should be prepared for middle of next year. They don't want politics to influence the safety of it. Releasing a vaccine that would cau

by takeda 6y ago

I heard somewhere that we should be prepared for middle of next year. They don't want politics to influence the safety of it. Releasing a vaccine that would cause damage would be devastating for the company. I'm wondering how do they test it, do they inject volunteers with the vacine, and they tell them to go infect themselves with a virus that 1 time out of 100 will kill them and an unknown percentage disable them?

darkerside 6y ago
Not to mention people's health...
deleted 6y ago
[deleted]
dmoy 6y ago
> I'm wondering how do they test it, do they inject volunteers with the vacine, and they tell them to go infect themselves with a virus that 1 time out of 100 will kill them and an unknown percentage disable them? Obviously no They get a large set of people (tens of thousands), half placebo, and then check rates afterwards.
- loeg 6y ago
  The larger the set the faster the results, but a large set is expensive. "Afterwards" is sort of a simplification. The study arms are compared regularly throughout in case the study needs to be ended one way or the other (Data and Safety Monitoring Committee). (If the vaccine is effective: great, we want to ramp up production and give it to everyone ASAP. If the vaccine is ineffective or has very bad side effects, we also want to conclude the study.)
loeg 6y ago
> I'm wondering how do they test it, do they inject volunteers with the vacine, and they tell them to go infect themselves with a virus that 1 time out of 100 will kill them and an unknown percentage disable them? No, and this is why Phase III trials take a long time, potentially a very long time if we actually get a handle on the virus with measures like masking and social distancing. Here's the protocol: 1. Volunteers get the vaccine (experimental arm) or a placebo (control arm). 2. They go about their lives. 3. Both study arms report any cases of COVID they develop. Also, any deleterious symptom (potential side effects). 4. If the vaccine arm has a statistically significant reduction in infection rates, and/or severity, everyone wins and the study is concluded. This process can take years if the background rate of infection is low enough.
- takeda 6y ago
  Thank you for the explanation.
- adrianb 6y ago
  > This process can take years if the background rate of infection is low enough. This is why the phase 3 trials tend to be organised in countries with high rates of infection, such as Brazil, South Africa or India. In locations with low rates of infection it's too likely that the people in the experimental group don't get infected simply because they don't get exposed to the virus.
  - takeda 6y ago
    > This is why the phase 3 trials tend to be organised in countries with high rates of infection, such as Brazil, South Africa or India. Or US (we are still higher than Brazil in cases per million). South Africa or India are actually much lower than us.
- nfw2 6y ago
  I can see why it may take years to determine if the infection rate has been significantly lowered. But what is the timeline for determining if there are serious deleterious symptoms? If we get to the point where we know a bunch of vaccines are safe, but not necessarily effective, could these be approved for anyone who understands the risks?
  - refurb 6y ago
    Adverse events are monitored continuously as long as the patient is still a part of the trial (which often extends past approval). Once the product is approved, the FDA has an adverse event monitoring system that collects reports and analyzes them for signals that might imply a previously-unknown adverse event. Of course it take more than just one case to for a new signal to be identified (unless it's really obvious like the patient dies right after getting the vaccine), so sometimes it may be a year or more until there is enough data to say "yes, we know nearly all the risks associated with this vaccine".
nradov 6y ago
No one will be told to go intentionally infect themselves. There will be no human virus challenge trials in the US as that would obviously never pass a review board. Instead they will vaccinate a study group and then compare infections, symptoms, and deaths versus a control group. The best estimate of infection fatality rate is 0.65%, not 1%. https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...
- orwin 6y ago
  I think this is the right IFR for the US, maybe a confidence interval is necessary however. In early April, data scientists paid by ARSGE calculated the IFR in france based on the diamond princess and found .7%, +- .2%, and estimated the high early IFR in spain and Italy was due to missing asymptomatic people and mismanagement. This pdf should still be available. US having a relatively younger population, .65% seems correct.

by takeda 6y ago

darkerside 6y ago

Not to mention people's health...

deleted 6y ago

[deleted]

dmoy 6y ago

loeg 6y ago
The larger the set the faster the results, but a large set is expensive. "Afterwards" is sort of a simplification. The study arms are compared regularly throughout in case the study needs to be ended one way or the other (Data and Safety Monitoring Committee). (If the vaccine is effective: great, we want to ramp up production and give it to everyone ASAP. If the vaccine is ineffective or has very bad side effects, we also want to conclude the study.)

loeg 6y ago

> I'm wondering how do they test it, do they inject volunteers with the vacine, and they tell them to go infect themselves with a virus that 1 time out of 100 will kill them and an unknown percentage disable them? No, and this is why Phase III trials take a long time, potentially a very long time if we actually get a handle on the virus with measures like masking and social distancing. Here's the protocol: 1. Volunteers get the vaccine (experimental arm) or a placebo (control arm). 2. They go about their lives. 3. Both study arms report any cases of COVID they develop. Also, any deleterious symptom (potential side effects). 4. If the vaccine arm has a statistically significant reduction in infection rates, and/or severity, everyone wins and the study is concluded. This process can take years if the background rate of infection is low enough.

takeda 6y ago
Thank you for the explanation.
adrianb 6y ago
> This process can take years if the background rate of infection is low enough. This is why the phase 3 trials tend to be organised in countries with high rates of infection, such as Brazil, South Africa or India. In locations with low rates of infection it's too likely that the people in the experimental group don't get infected simply because they don't get exposed to the virus.
- takeda 6y ago
  > This is why the phase 3 trials tend to be organised in countries with high rates of infection, such as Brazil, South Africa or India. Or US (we are still higher than Brazil in cases per million). South Africa or India are actually much lower than us.
nfw2 6y ago
I can see why it may take years to determine if the infection rate has been significantly lowered. But what is the timeline for determining if there are serious deleterious symptoms? If we get to the point where we know a bunch of vaccines are safe, but not necessarily effective, could these be approved for anyone who understands the risks?
- refurb 6y ago
  Adverse events are monitored continuously as long as the patient is still a part of the trial (which often extends past approval). Once the product is approved, the FDA has an adverse event monitoring system that collects reports and analyzes them for signals that might imply a previously-unknown adverse event. Of course it take more than just one case to for a new signal to be identified (unless it's really obvious like the patient dies right after getting the vaccine), so sometimes it may be a year or more until there is enough data to say "yes, we know nearly all the risks associated with this vaccine".

nradov 6y ago

No one will be told to go intentionally infect themselves. There will be no human virus challenge trials in the US as that would obviously never pass a review board. Instead they will vaccinate a study group and then compare infections, symptoms, and deaths versus a control group. The best estimate of infection fatality rate is 0.65%, not 1%. https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena...

orwin 6y ago
I think this is the right IFR for the US, maybe a confidence interval is necessary however. In early April, data scientists paid by ARSGE calculated the IFR in france based on the diamond princess and found .7%, +- .2%, and estimated the high early IFR in spain and Italy was due to missing asymptomatic people and mismanagement. This pdf should still be available. US having a relatively younger population, .65% seems correct.