> it was only possible because of that earlier work on the closely related SARS protease - and remember, at the time (and for some years thereafter!) that work

> it was only possible because of that earlier work on the closely related SARS protease - and remember, at the time (and for some years thereafter!) that work looked like wasted effort for the most part. After all, there was no SARS to treat, and there were no other related coronaviruses out there causing trouble. But that's science: once you discover something, it stays discovered (or it had better, anyway), and that knowledge is out there waiting to be put to a new use. This also somewhat applies to mRNA technology. It was initially being worked on for cancer treatments and (as far as I am aware) not seriously considered for vaccines.