[jyxent]

I guess it depends what endpoint you are talking about. The actual vaccine was pretty quick, it was the phases of testing that took longer: https://www.sec.gov/Archives/edgar/data/1682852/000119312520...

[rzzzt]

Also the starting point. IIRC the technology already existed for SARS-CoV-1, but it went on a hiatus before producing a vaccine became necessary.