A general sense I have–and I could be wrong–is that people think vaccine deployment will happen rapidly (though it’s worth noting that the Surgeon General has tried to be more realistic about the timeline). Looking at various sources, this is what I’ve been able to determine as to the number of vaccines that will be available in the U.S.:
Moderna: 200 million doses
Pfizer: 200 million doses (170 million by June 31, 30 million more by July 31)
Johnson & Johnson: 100 million doses (still in phase 3)
AstraZeneca: 300 million doses (still in phase 3)
Novavax: 100 million doses (haven’t started phase 3)
Sanofi/GSK: 100 million doses (haven’t started phase 3)
(any two-shot vaccine requires two doses, so Moderna would be able to vaccinate 100 million people).
I’m sorry to be a downer here, but I just don’t see how we can think we’ll hit 50% vaccination until June or July. We still don’t know how AstraZeneca’s or Johnson & Johnson’s trials will turn out; Sanofi/GSK might not even reach phase 3.
Yes, we have to get through winter, but spring and perhaps even summer could be horrible too.