Pfizer and BioNTech Conclude Phase 3 Study of Covid-19 Vaccine Candidate
41,135 Total enrolled<p>~20,567 in each arm<p>162/20,567 cases in the placebo arm (~0.79%)<p>8/20,567 cases in the vaccine arm (~0.04%)<p>Absolute risk reduction of ~0.75% (over the time period of the study, which is difficult to tell).<p>Number-needed-to-Treat (NNT): 134 vaccinations to prevent 1 symptomatic case over the study duration.<p>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)