[jyl]

What I'm struggling with is, how does a new SARS2 vaccine get developed after mid-2021. There will be multiple existing vaccines. Ethically the new vaccine trials will have to be against an existing vaccine. If the existing vaccine is 90% effective, what study size / duration will be needed to show superiority with adequate statistical power? Even if FDA permits non inferiority, will need even bigger trials than the 30-44K phase 3s that PFE and MRNA did. If the infection rate is down a lot in the US, will need even larger trials. Who can pay for a 80-100K subject trial? Okay, you go to a developing country. But AZN is there with its vaccine, that it sublicensed to Serum India and others, and that it committed to sell for the first year at or near cost. Most vaccine markets have only a few players. SARS2 may end up dominated by the few who got approved first: PFE MRNA AZN and maybe JNJ or one other. Speed really was of the essence here. PFE knew that, it signed up BNTX, skipped OWS funding, threw four candidates into the clinic and pulled out all the stops to get one over the finish line. Who cares about the cold chain requirements, they can reformulate after they get on the market. MRNA also knew that. AZN may have been cleverest of all, using sell-at-cost to block other entrants in year 1, then it'll raise prices.

There is a long list of other SARS2 vaccines being developed. I suspect that unless they have huge advantages in administration (inhalation etc), or unless 90% isn't actually 90%, almost all will be abandoned. Maybe JNJ or NVAX sneak in before the door shuts. If they don't get their trials mostly done by early 2021, they may get left in the cold.

That's my cynical take on this.