The trial included more than 10,000 fully vaccinated people, age 16 and older, who randomly received either the 30-microgram booster dose of vaccine or a placebo. The median time between completing their initial second dose of vaccine and receiving a booster or placebo was about 11 months, the companies said.
Pfizer and BioNTech reported that during the study, there were 109 Covid-19 cases among people who received a placebo and five cases among those who received the third dose of vaccine. The companies noted that the vaccine efficacy they found, of 95.6%, reflects that reduction of disease among those who received a booster shot versus those who did not. These are the first results from a randomized, controlled Covid-19 vaccine booster trial, the companies said, and they reflect a period when the highly contagious Delta variant was prevalent.
“In addition to our efforts to increase global access and uptake among the unvaccinated, we believe boosters have a critical role to play in addressing the ongoing public health threat of this pandemic,” Bourla said. “We look forward to sharing these data with health authorities and working together to determine how they can be used to support the rollout of booster doses around the world.”
Now, the US Centers for Disease Control and Prevention’s vaccine advisers, the Advisory Committee on Immunization Practices, meet Thursday to decide on whether to recommend the FDA’s recent mix-and-match authorization — as well as the authorization of Moderna and J&J boosters — and then the CDC director will decide whether to sign off on ACIP’s guidance