2. So how did Pfizer arrive at 95% efficacy?
Of the 170 participants, ALL tested positive for Covid, but:
—162 received a Placebo
— 8 received 2 doses of mRNA
Divide 162/170 = 95% efficacy (according to Pfizer) which is how they met the criteria for EUA approval. #Covid19
https://twitter.com/TexasLindsay_/status/1610695674781372418