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Pfizer Covid-19 Vaccine: Is It The Breakthrough We Hoped For?

Pfizer and its partner BioNTech say their coronavirus vaccine is 90 percent effective in Phase III trials. How excited should we be about the news and what questions go unanswered?


November 9, 2020

By Graham Lawton

A health worker in Turkey holds a syringe in hand during the Phase III trial of the coronavirus vaccine candidate developed by Pfizer and BioNTech

Photo by Dogukan Keskinkilic / Anadolu Agency via Getty Images

US drug maker Pfizer and its German partner BioNTech today published some positive-looking clinical trial results with their experimental Covid-19 vaccine BNT162b2.

The headline is “90 percent effective”. But that may not be as good news as it first appears.

What did Pfizer and BioNTech find?

The results come from a phase III clinical study, the final phase of testing whether a …