At least for the Pfizer study, no Covid-19–associated deaths were observed in the study or control groups so this says more about COVID and the study than about the vaccine itself.
> BNT162b2 was 95% effective in preventing Covid-19 (95% credible interval, 90.3 to 97.6).
Yet the deaths clearly mattered when multiplied up to population scale, because COVID was able to fill up the hospitals.