Interesting, Metaculus was overly pessimistic about the timeline for the COVID-19 vaccine, but not absurdly so considering that predictions closed on May 2020:

https://www.metaculus.com/questions/3860/when-will-a-vaccine-targeted-at-the-2019-novel-coronavirus-covid-19-be-administered-to-at-least-10m-people/

How many people 11 months ago would have put even 25% probability of widespread vaccination by March 2021?