For months, Pfizer CEO Albert Bourla had maintained that the company would know this month whether its BioNTech-shared COVID-19 vaccine works. But top scientists pushed back, the FDA released detailed guidelines and critics grew increasingly louder.
Now, finding himself alone in the biopharma world with that bullish estimate, the Big Pharma chief is changing his tone.
Pfizer won’t apply for FDA emergency use authorization before the third week of November, Bourla wrote in an open letter on Friday.
What about October? That’s when the company might know whether the vaccine, dubbed BNT162, is effective, but the company still needs to gather enough safety data for an application, Bourla explained.
That’s a clear shift from Bourla’s previous comments, which constantly featured “October” as the key word—at a time when President Donald Trump was touting a vaccine before the Nov. 3 election, and mentioning Pfizer by name.
“Right now, our model, our best case, predicts that we will have an answer by the end of October,” Bourla previously said on the “Today” show. During a digital event in September, he also said the company expected initial results in late October and would seek FDA authorization as soon as possible. In October, “the truth will be revealed,” was what he told The Washington Post.
That October timeline sounded even more aggressive when Moderna CEO Stephane Bancel, known for touting ambitious goals, said his company’s shot, which was the first in the U.S. to move into clinical testing, likely wouldn’t have data until November.
Then, in late September, more than 60 researchers and bioethicists urged Pfizer to wait until late November at earliest to file its vaccine for FDA review, arguing a submission before accruing at least two months of safety data would “severely erode public trust and set back efforts to achieve widespread vaccination.”
For an emergency use application, the FDA is requiring at least two months of safety data on half of the trial participants after their final vaccine doses, according to a guidance document released last week.
To understand the vaccine’s efficacy—that is, whether it can protect individuals from COVID-19—a certain number of COVID-19 cases in the phase 3 trial need to be counted before investigators can compare the effectiveness of the vaccine with placebo. That means the data may come earlier—by October—if infections come quickly, Bourla explained in the open letter.
But effectiveness is only one of three metrics Pfizer will use for applying its vaccine for public use, he added. “Safety is, and will remain, our number one priority, and we will continue monitoring and reporting safety data for all trial participants for two years,” he said.
What’s more, the company will also gather manufacturing data to demonstrate “the quality and consistency of the vaccine that will be produced,” Bourla said. And that information will be ready before the safety readout, he said.
Despite his previous timeline falling in line with Trump’s, Bourla has said Pfizer is only “moving at the speed of science,” not politics. “In this hyper-partisan year, there are some who would like us to move more quickly and others who argue for delay,” he wrote in another open letter earlier this month. “Neither of those options are acceptable to me.”