That's such a naive way to look at it. It's not like we could've known beforehand which type of vaccine would be more effective. Some tried mRNA, other tried ot

That's such a naive way to look at it. It's not like we could've known beforehand which type of vaccine would be more effective. Some tried mRNA, other tried other techniques, and they all have to go through a lengthy phase 3 trial. This is a novel virus, and if everyone just did one kind of vaccine, and that kind failed, they we would've been fucked. Hell, it's even more complex than that, because even given a type of vaccine, even subtle stuff such as dose size and time between the two doses seem to play a huge role, and this is again something that needs to be tweaked over time, using long phase 3 trials. I would attribute it much more to luck than actual skills here.