Will Pfizer’s Vaccine Be Ready in October? Here’s Why That’s Unlikely.

“They will not get approved before the election,” said Ronny Gal, an analyst with the Wall Street firm Bernstein. “The timing just doesn’t work.”

One key to understanding how Pfizer vaulted to first place in the vaccine race is found in its trial blueprints, known as a protocol.

Even though Moderna and Pfizer began their trials on the same day, Pfizer’s is “built for speed,” as one Wall Street firm, SVB Leerink, described it.

Participants in Pfizer’s trial are given two doses of a vaccine 21 days apart, whereas those in Moderna’s wait 28 days in between. Pfizer begins looking for sick volunteers seven days after the second dose, whereas Moderna does so at 14 days. And Pfizer’s plan allows an outside review panel to look at early data after just 32 volunteers have become ill with Covid-19. Moderna’s plan doesn’t allow for a first peek until 53 cases.

Some experts have speculated that Pfizer’s volunteers happen to be in places where the virus is spreading quickly, making it more likely that they would have been exposed to the virus and put the vaccine to the test. While Moderna’s trial is being conducted only in the United States, Pfizer’s is international, with locations set up or planned in the United States, Brazil, Turkey and Argentina.

In Argentina, which has seen a surge of coronavirus infections since August, 33,000 volunteers quickly signed up for about 4,500 slots, said Dr. Fernando Polack, the head researcher of the Pfizer study that is being carried out at the Hospital Military Central in Buenos Aires.

“We have a lot of years of experience in these kinds of trials, and we’ve never seen these numbers before,” Dr. Polack said in an interview. He declined to comment on whether he was aware of any Covid-19 cases among volunteers.

Article source: https://www.nytimes.com/2020/09/30/health/pfizer-covid-vaccine.html