General Discussion
Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsLong-Term Studies Of COVID-19 Vaccines Hurt By Placebo Recipients Getting Immunized
From an NPR article in February
https://www.npr.org/sections/health-shots/2021/02/19/969143015/long-term-studies-of-covid-19-vaccines-hurt-by-placebo-recipients-getting-immuni
RICHARD HARRIS
February 19, 2021 5:00 AM ET
"Tens of thousands of people who volunteered to be in studies of the Pfizer-BioNTech and Moderna COVID-19 vaccines are still participating in follow-up research. But some key questions won't be easily answered, because many people who had been in the placebo group have now opted to take the vaccine.
***************************************
Mott was one of about 650 volunteers who took the experimental Moderna vaccine at a company called Johnson County Clinical Trials in Lenexa, Kan. Dr. Carlos Fierro, who runs the study there, says every participant was called back after the Food and Drug Administration authorized the vaccine.
"During that visit we discussed the options, which included staying in the study without the vaccine," he says, "and amazingly there were people a couple of people who chose that."
He suspects those individuals got spooked by rumors about the vaccine. But everybody else who had the placebo shot went ahead and got the actual vaccine. So now Fierro has essentially no comparison group left for the ongoing study.
"It's a loss from a scientific standpoint, but given the circumstances I think it's the right thing to do," he says.
People signing up for these studies were not promised special treatment, but once the FDA authorized the vaccines, their developers decided to offer the shots.
Dr. Steven Goodman, a clinical trials specialist at Stanford University, says losing those control groups makes it more difficult to answer some important questions about COVID-19 vaccines.
"We don't know how long protections lasts," he says. "We don't know efficacy against variants for which we definitely need a good control arm and we also don't know if there are any differences in any of these parameters by age or race or infirmity."
Related link: https://www.democraticunderground.com/100215792289
hlthe2b
(102,357 posts)trials when the medication (in this case, vaccine) is found to be overwhelmingly beneficial against a serious disease or potentially deadly infection. Human Subjects Review Boards that review such research, as well as FDA in the Emergency Investigational authorization, require this to be the case.
But, yes, we do lose some valuable prospective data in the process.
Pobeka
(4,999 posts)Understanding of course the linkage between serum studies and realized efficacy is not necessarily 1:1
hlthe2b
(102,357 posts)We still have not isolated the most important and specific neutralizing antibody (s) (we just group those antibodies that appear to neutralize the virus in the lab) nor the threshold at which most are "protected." So if we do serosurveys in highly vaccinated populations, that data can still be misleading.
This is something that we are able to determine fairly readily for most other pathogens--that allows us to create simple dichotomous antibody tests (yes, antibodies present AND sufficient vs no), but the mutability of SARS-COV2 has really complicated that basic research. And while we know both B-cell memory and T-cell activation is probably considerably longer than the longevity of continually produced circulating antibodies, we certainly don't know the duration of the former. That's why the lack of consensus on WHEN to booster. We can say when levels of neutralizing antibodies have dropped, but if B-cell memory is intact it could simply be hours or days before exposure would lead to sufficient antibody production again (in time to stop the virus before serious illness develops). For those immunologists who believe that the latter is sufficient to prevent most hospitalization/death, they might argue against the imminent need for booster doses or at least a longer duration in the current 5 month-8 month argument. But undoubtedly for some, including the immunocompromised, the b-cell memory may not be "strong" or long-lasting. arguing again for a boosted response sooner.
To be honest (and not wanting to advocate exploiting the undeveloped and thus less vaccinated world), but those more "virgin" populations can provide one hell of a lot of data on the natural immune response, its natural course, duration, and longevity. Hopefully, some countries are able to follow these populations, even while working to secure the vaccines that theyso clearly need.
Pobeka
(4,999 posts)FrankBooth
(1,606 posts)One trick pony.
WhiskeyGrinder
(22,431 posts)MisterNiceKitty
(422 posts)FakeNoose
(32,748 posts)They were looking for volunteers for the testing program in Pittsburgh about a year and a half ago. I put my name in because I thought I'd be a good candidate - almost 70 years old, no health issues, not a smoker, and I hadn't been exposed or infected by Covid.
For whatever reason, I wasn't chosen for the program. However if I had been chosen, I still would have wanted to receive the vaccine even if I got the placebo in the test. It only makes sense. Otherwise why would anyone volunteer to be a guinea pig?
ms liberty
(8,596 posts)We know far more today about the virus and the vaccines than we did then, and the experts are still studying it, they didn't just quit as soon as the vaccines were created. Posting outdated material wastes our time.