Thread by @nataliexdean

Really appreciate this from @StevenSalzberg1. There are important debates about how we do (or do not do) things differently during emergencies, and I think it is good for the public to see the pros and cons laid out.

https://twitter.com/StevenSalzberg1/status/1290314921264189440

My colleagues and I have spent a lot of time thinking about these issues, and the rules are not set in stone. There are settings where there is more flexibility.
who.int/docs/default-s…

But what features of Covid vaccines convince me that we need Phase 3 trials?
(1) Insufficient safety data. We only have reports from relatively small trials, and so side effects are not well characterized.
statnews.com/2020/07/27/cov…

(2) Who will receive the vaccine? Some vaccines are used reactively to squash outbreaks (e.g. ring vaccination). The risk/benefit profile is different for someone known to be exposed than someone who is not at immediate risk. We are talking about general population vaccines.

(3) We do not understand the immune dynamics of infection. It is a new virus! So we don't know what level of antibodies is protective, and there is a small theoretical risk that a vaccine could increase risk. We can only rule this out with proper trials.

(4) Because the disease is so widespread, vaccine trials are not only possible, they can be done quickly. If it would take following 100,000+ participants a decade to get answers, then that is a very different discussion than a 3-6 month trial.

There are diseases where alternative approval pathways make sense (rabies, anthrax, Nipah virus). But with millions to be vaccinated, the stakes are too high here to rush the process. For more, read my op-ed (written over a week ago! but published today).
nytimes.com/2020/08/03/opi…