Jon CohenScience’s COVID-19 reporting is supported by the Pulitzer Center and the Heising-Simons Foundation.On Sunday evening, Kathrin Jansen was watching the sun set on the banks of the Hudson River in upstate New York with her husband when the head of Pfizer, Albert Bourla, phoned her cell with the update she eagerly awaited.
Jansen, who heads vaccine R&D at Pfizer, had learned that morning a massive placebo-controlled trial of the company’s candidate COVID-19 vaccine had a positive efficacy signal, but it wasn’t clear just then how strong it was.