evidence: Pfizer and BioNTech Announce Publication of Results from Landmark Phase 3 Trial of BNT162b2 COVID-19 Vaccine Candidate in The New England Journal of Medicine - Data from 43,448 participants, half of whom received BNT162b2 and half of whom received placebo, showed that the vaccine candidate was well tolerated and demonstrated 95% efficacy in preventing COVID-19 in those without prior infection 7 days or more after the second dose - Vaccine efficacy observed in the overall study population was also generally consistent across subgroups defined by age, gender, race, ethnicity, baseline body mass index (BMI), or presence of other underlying co-morbidities - Partial protection from the vaccine candidate appears to begin as early as 12 days after the first dose - These data were included in the requests for regulatory authorization submitted to regulatory agencies across the globe, including the U.S. Food and Drug Administration and the European Medicines Agency [...] The most common adverse events of BNT162b2 were transient, mild to moderate pain at the injection site, fatigue and headache, and these generally resolved within two days. These reactions were less common and milder in older adults than younger adults. Severe reactions (Grade 3) were reported in fewer than 2% of vaccine recipients after either dose except for fatigue (3.8%) and headache (2.0%). Fever (≥38 °C) was reported in similar proportions of younger (16%) and older (11%) vaccine recipients. Rates of serious adverse events were similar between vaccine and placebo groups (0.6% and 0.5%).There were no COVID-19 related deaths.