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This is normally right thinking but I'm not sure it's right today. Evidence based medicine is an important paradigm - we don't normally want to overstep our evidence. But those are normal times, normal rules. A 
(1/6) https://twitter.com/EricTopol/status/1345080202964029442
(1/6) https://twitter.com/EricTopol/status/1345080202964029442
Today we know that there is a new variant of SARS-CoV-2 that is 50-75% more infectious. The current dominant variant is already straining healthcare systems and 50-75% greater transmission has the potential to be catastrophic. (2/6)
We know that both mRNA vaccines work with two doses with greater than 95% efficacy. We know the Moderna vaccine is essential (short run) non-inferior at one dose and the Pfizer vaccine is probably as well. We aren't as sure and we have poor data on duration. (3/6)
But we don't have great data about duration for two doses. We don't have the way to accelerate time to know. We have worse data on one dose. We don't have time to be sure about anything. (4/6)
We have to make decisions under uncertainty. Will the vaccine last as long with 1 dose? Will the new variant become (already is?) widespread? Models can inform this and allow us to consider the different parameters and outcomes. (5/6)
Post-script: To some degree, this is all irrelevant in the US right now. We have tons of first doses that haven't been shipped. We have tons shipped that haven't been used. NYC only used something like 25% of received doses. We aren't even facing the 1 vs 2 constraint yet. (6/6)
