Here is the lowdown on Pfizer’s COVID-19 vaccine

Study gives efficacy 'estimates' by age and some comorbidities, although the data cannot be definitive, authors say

The long-awaited publication of peer-reviewed trial results of Pfizer’s mRNA COVID-19 vaccine has revealed evidence of the vaccine’s efficacy in patients aged 55-75 and other groups at high risk of severe disease.  

The study, published on Thursday in the New England Journal of Medicine, reports the data for about 44,000 participants across six countries in the phase III trial, half of whom received a saline injection as placebo.