Why Emergency COVID-Vaccine Approvals Pose a Dilemma for Scientists

November 23, 2020

(Nature) – Following the release of early data from phase III trials on 9 November, vaccine makers Pfizer and BioNTech have sought regulatory permission to deploy their vaccine under emergency-use rules. The developer of another leading vaccine, Moderna, is expected to do the same within weeks. Once a vaccine is granted emergency approval, there is pressure on developers to offer the immunization to trial participants who received a placebo. But if too many people cross over to the vaccine group, the companies might not have enough data to establish long-term outcomes, such as safety, how long vaccine protection lasts and whether the jab prevents infection or just the disease.