Interesting thread on single-dose trials. Worth reading to hear from some real public health leaders and Nate Silver.

Unfortunately, I don’t see a way forward for new single dose efficacy trials of approved vaccines. The only hope is establishing a correlate.

Here’s why 1/ https://twitter.com/mattyglesias/status/1343303615738470400

There’s no financial motivation on the part of the companies to invest in trials that could cut purchasing in half.

2/

There’s currently no motivation in OWS for such trials because J&J’s single-dose vaccine is already being evaluated in a large efficacy study. Beyond that NIAID resources are stretched too thin to add more major efficacy trials.

3/

You’d have to look internationally for study sites and funders. There’s a dearth of qualified international study sites that are not already involved in ongoing efficacy trials.

4/

Organizing trials w 10s of thousands of participants takes huge effort and time. If not already underway, not sure an answer on single dose will come before J&J, AZ (US) and NovaVax report and are (likely) approved rendering supply and cold chain issues less critical.

5/

Best hope for approval of single dose vaccines is:
1. Good readout for J&J (duh)
2. Establishing an immune correlate that is lower than levels seen in convalescent serum.

6/

I hate to be Debbie Downer about this and I hope to be proven wrong, but I just don’t see single-dose efficacy trials in the cards.

Will be interesting to ponder how we can encourage supply chain considerations in development of vaccines in a future pandemic.

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