The company said it will seek emergency authorization "within days." If approved, Pfizer would likely make history for having the first FDA-approved COVID-19 vaccine. CNN: Pfizer And BioNTech Say Their Coronavirus Vaccine Was 95% Effective With No Safety Concerns A final analysis of the Phase 3 trial of Pfizer's coronavirus vaccine shows it was 95% effective in preventing infections, even in older adults, and caused no serious safety concerns, the company said Wednesday. The company counted 170 cases of coronavirus infection among volunteers who took part in the trial. It said 162 infections were in people who got placebo, or plain saline shots, while eight cases were in participants who got the actual vaccine. That works out to an efficacy of 95%, Pfizer said. The data show Pfizer's initial claim of a better than 90% efficacy -- a claim that stunned and pleased health officials and vaccine developers last week -- holds up.