Pfizer representatives told the FDA advisory panel that they planned to unblind trial participants and offer vaccine to the placebo group when it was their turn outside the trial. ... “I think it's very important that we unblind the trial at once and offer the placebo group vaccines,” Slaoui said at the briefing.

What is the difference between Pfizer and Moderna vaccine?

Moderna's shot contains 100 micrograms of vaccine, more than three times the 30 micrograms in the Pfizer shot. And Pfizer's two doses are given three weeks apart, while Moderna's two-shot regimen is administered with a four-week gap.

What happens to other COVID-19 vaccines being studied?

FDA believes it is important for clinical trials for other COVID-19 vaccines to continue or initiate. It is important to have a portfolio of COVID-19 vaccines available to be able to vaccinate our population.