Researchers Urge Delaying Pfizer Vaccine’s Second Dose as First Highly Effective

February 19, 2021

(Reuters) – The second dose of Pfizer Inc’s COVID-19 vaccine could be delayed in order to cover all priority groups as the first one is highly protective, two Canada-based researchers said in a letter published in the New England Journal of Medicine. The vaccine had an efficacy of 92.6% after the first dose, Danuta Skowronski and Gaston De Serres said, based on an analysis of the documents submitted by the drugmaker to the U.S. Food and Drug Administration (FDA).