Pfizer is on track to be first to find out if its Covid vaccine works

A wide range of symptoms and severity makes the evaluation of Covid-19 vaccines tricky. The U.S. Food and Drug Administration has said that to be approved, vaccines should cut the number of symptomatic cases by half. Yet documents released by the drugmakers show each has its own approach to defining which symptoms count, and when to count them.
Source: The Economic Times Healthcare and Biotech News - Category: Pharmaceuticals Source Type: news