Studies of millions of people, with the same place and time, provide fairer comparisons than clinical trials do
A FEW MONTHS ago the biggest question about covid-19 vaccines was whether any of them would work. Today the problem in some countries is having too many to choose from. In Europe some people are spurning AstraZeneca’s jab, preferring to wait for Pfizer’s or Moderna’s instead.
This article appeared in the Graphic detail section of the print edition under the headline “Six of one”
From the March 6th 2021 edition
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