Pfizer CEO Albert Bourla says they have a "strict policy" that they will not announce data — good or bad — on their COVID vaccine until it's published in a scientific journal.

"This is the reason why you haven't heard from us," he tells @megtirrell. "But you will of course."

On planning the Phase 3 trial, Bourla anticipates having 100+ research sites with vast majority in the US.

That trial will enroll 30,000 people overall, "predominantly in the US" but also recruiting globally.

Bourla says there has been no evidence of antibody-dependent enhancement in the early data.

That has been a potential concern that a vaccine may give an insufficient immune response that actually worsens the disease severity.

"Pfizer will never cut corners," CEO Bourla says. "And Pfizer will never put out a vaccine, no matter who is pressing us" if its scientists do not believe it is safe and efficacious.

"We are part of Warp Speed," Bourla says. "We don't take money because we don't need money."

Bourla says taking govt funding would slow down Pfizer's research. Emphasizes it is about return-on-effort, not return-on-investment for its coronavirus vaccine

"I am aware that right now billions of people, millions of businesses, hundreds of governments are investing their hope for a solution to a handful of pharma companies ... That puts a lot of weight on my soul," says Pfizer CEO Albert Bourla