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FDA authorizes one-dose Covid-19 vaccine

Exmoor 6y ago
20 million US doses planned on delivery in March, 100 million "by June". Very curious to see how states will choose to treat this with regards to eligibility. Open it up to a slightly younger cohort at lower risk? Treat it exactly the same as the mRNA vaccines?
- valarauko 6y ago
  My guess is that J&J with its easier logistics might end up being prioritized for rural & smaller communities. I doubt vaccine centers will have multiple vaccine types on hand to selectively give people based on an individualized risk assessment - you get what you get.
- maxerickson 6y ago
  I think between vaccinations that are complete and people not being sure about it, the criteria are going to be pretty broad by the end of April. It is fascinating to watch younger internet people shoot for their appointments while not enough vaccine has been sent here to do first doses for the compiled waiting list of older folks.
stanrivers 6y ago
Once again, science saves the day! Glad to see the FDA move quickly and prioritize things. Good work to all involved.
- credit_guy 6y ago
  > FDA move quickly and prioritize things Move quickly? Are you being sarcastic? What the heck is wrong with the FDA? They knew about this vaccine trial, everyone in the whole world knew. They were supposed to keep an eye on the trial and get data "live" and analyze it before J&J actually submitted for approval. Once they submitted, what took them so long? They are not running any experiments, they are simply reading a report. This is the third such report after Pfizer and Moderna. They have fresh experience with reading a report and coming up with all the possible challenges. It is their freaking job to understand p-values and significance levels. 1 month to read a report and say "yes, it looks good"? Are you kidding me?
BurningFrog 6y ago
Does anyone know why this vaccine "only requires one dose"? Is the number of doses just an arbitrary decision by the manufacturers, or is it determined by the technology somehow?
- valarauko 6y ago
  One takeway from the Pfizer & Moderna trials was that a single dose of those vaccines were also fairly protective for most people. With those vaccines, if you could avoid being infected within two weeks of the first dose, it looks like the protection is ~ 90% against COVID. The second dose acts as a booster, and with J&J, a second dose does indeed increase the antibody titre about three fold. That said, a single dose of any of these vaccines is probably "good enough". Couple of caveats: With Pfizer & Moderna, the major difference in outcome for single dose participants was a reduced protection from 'severe COVID', down to about 50%. It's also a very small group (~1000 people), so there's the risk of over interpreting the results. The other thing to consider is that a second dose might be required for older adults, who have a reduced immune response from a single dose.
- maxerickson 6y ago
  It's not arbitrary, but it's part of the design of the Phase 3 trial. One of the goals of the Phase 1 trial is to figure out the dosing, both the size and whether there is a booster needed and so on. J&J has started a trial to evaluate adding a second dose. And of course there's lots of talk about delaying the 2nd doses of the other vaccines. It's likely enough they could have been approved as single dose vaccines. It'd be fascinating to have some insight into the conversations they had while deciding what dosing to trial.
  - BurningFrog 6y ago
    > It's not arbitrary, but it's part of the design of the Phase 3 trial. What I'm trying to understand is if there is any inherent difference that makes one vaccine suitable for one dose and another for two doses. I still haven't seen anything answering this.

20 million US doses planned on delivery in March, 100 million "by June". Very curious to see how states will choose to treat this with regards to eligibility. Open it up to a slightly younger cohort at lower risk? Treat it exactly the same as the mRNA vaccines?

valarauko 6y ago
My guess is that J&J with its easier logistics might end up being prioritized for rural & smaller communities. I doubt vaccine centers will have multiple vaccine types on hand to selectively give people based on an individualized risk assessment - you get what you get.
maxerickson 6y ago
I think between vaccinations that are complete and people not being sure about it, the criteria are going to be pretty broad by the end of April. It is fascinating to watch younger internet people shoot for their appointments while not enough vaccine has been sent here to do first doses for the compiled waiting list of older folks.

stanrivers 6y ago

Once again, science saves the day! Glad to see the FDA move quickly and prioritize things. Good work to all involved.

credit_guy 6y ago
> FDA move quickly and prioritize things Move quickly? Are you being sarcastic? What the heck is wrong with the FDA? They knew about this vaccine trial, everyone in the whole world knew. They were supposed to keep an eye on the trial and get data "live" and analyze it before J&J actually submitted for approval. Once they submitted, what took them so long? They are not running any experiments, they are simply reading a report. This is the third such report after Pfizer and Moderna. They have fresh experience with reading a report and coming up with all the possible challenges. It is their freaking job to understand p-values and significance levels. 1 month to read a report and say "yes, it looks good"? Are you kidding me?

BurningFrog 6y ago

Does anyone know why this vaccine "only requires one dose"? Is the number of doses just an arbitrary decision by the manufacturers, or is it determined by the technology somehow?

valarauko 6y ago
One takeway from the Pfizer & Moderna trials was that a single dose of those vaccines were also fairly protective for most people. With those vaccines, if you could avoid being infected within two weeks of the first dose, it looks like the protection is ~ 90% against COVID. The second dose acts as a booster, and with J&J, a second dose does indeed increase the antibody titre about three fold. That said, a single dose of any of these vaccines is probably "good enough". Couple of caveats: With Pfizer & Moderna, the major difference in outcome for single dose participants was a reduced protection from 'severe COVID', down to about 50%. It's also a very small group (~1000 people), so there's the risk of over interpreting the results. The other thing to consider is that a second dose might be required for older adults, who have a reduced immune response from a single dose.
maxerickson 6y ago
It's not arbitrary, but it's part of the design of the Phase 3 trial. One of the goals of the Phase 1 trial is to figure out the dosing, both the size and whether there is a booster needed and so on. J&J has started a trial to evaluate adding a second dose. And of course there's lots of talk about delaying the 2nd doses of the other vaccines. It's likely enough they could have been approved as single dose vaccines. It'd be fascinating to have some insight into the conversations they had while deciding what dosing to trial.
- BurningFrog 6y ago
  > It's not arbitrary, but it's part of the design of the Phase 3 trial. What I'm trying to understand is if there is any inherent difference that makes one vaccine suitable for one dose and another for two doses. I still haven't seen anything answering this.