Pfizer and BioNTech Conclude Phase 3 Study of Covid-19 Vaccine Candidate
41,135 Total enrolled~20,567 in each arm162/20,567 cases in the placebo arm (~0.79%)8/20,567 cases in the vaccine arm (~0.04%)Absolute risk reduction of ~0.75% (over the time period of the study, which is difficult to tell).Number-needed-to-Treat (NNT): 134 vaccinations to prevent 1 symptomatic case over the study duration.Keep in mind, this is over some time period. Annualized, these numbers would almost certainly increase. We don’t know how many days/weeks/months it took to reach 162 / 8 cases respectively (something between ~5-6 months and ~5 days)