CNN CNN Films Race for the Vaccine May 16, 2021 02:10:00
Pfizer now moves to phase three trials, involving tens of thousands of people. usually after early trials with just a handful of volunteers, the next step would be phase two with a few hundred. but again, given the urgency, these steps are all now happening at once. >> we care for the quality looking carefully at safety, all of this was normal routine procedure. the process never changed. it's how we compressed time and how we did parallel work. that's really what changed. >> to a truth, the huge numbers necessary, pfizer has dozens of phase three trial sites all over the world and new york ci...