I just want to confirm here that you are asserting that COVID-19 appeared in March 2020? Obviously this is not the case or it would be called COVID-20.
Nobody was developing vaccines for it in 2019. I forget when it was sequenced, I suppose that probably happened a little earlier. But it doesn't take much guesstimation to say that vaccine development wouldn't have started in earnest until a little way through 2020.