Pfizer proposes expansion of experimental phase-three vaccine trial

Pfizer proposes expansion of experimental phase-three vaccine trial
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Pfizer proposes the expansion of its experimental phase-three vaccine trial to register up to 44,000 participants.

The vaccine trial expansion suggests a significant increase from the company’s previous target of 30,000.

The experimental Covid-19 vaccine from Pfizer could be distributed in the US before the end of the year once proven safe and effective, according to CEO Albert Bourla.

Pfizer is expected to have key data from its phase three trial for the Food and Drug Administration by the end of October, Bourla told CBS’ “Face the Nation.”

He explained that if the agency approves the potential vaccine, the company would prepare “hundreds of thousands of doses,” he said.


US health authorities and drugmakers have been speeding up Covid-19 development by investing in various stages of research even though doing so could be for nothing if the vaccine is not proven safe and effective.

Pfizer has been working alongside German drugmaker BioNTech. On Sunday, Bourla mentioned that the company has sealed $1.5 billion for the development of the vaccine. He added that if the vaccine did not work, it would be financially “painful” for the company.

“At the end of the day, it’s only money. But that will not break the company, although it’s going to be painful,’” he noted.


Pfizer late-stage testing may produce results as early as October, according to Bourla’s announcement.

There are already 23,000 volunteers for the Pfizer late-stage testing that started in late July, Bourla said during an interview with the International Federation of Pharmaceutical Manufacturers & Associations, a trade group. The CEO of the pharmaceutical company said they plan to enroll at least 30,000 participants.

“We expect by the end of October, we should have enough … to say whether the product works or not,” he said.

US health officials have previously announced that findings from late-stage testing could be available in November or sooner.

Pfizer’s potential Covid-19 vaccine is one of three supposed by the US that is currently in late-stage testing. Pfizer has been working on its candidate vaccine with German drugmaker BioNTech. Their potential vaccine involves the use of a genetic material called messenger RNA, or mRNA. In July, the company announced promising data from its early-stage trial.

Not cutting corners

Meanwhile, drug company executives, including from Pfizer, stressed they are not cutting corners to develop vaccines. They noted that the Food and Drug Administration has not relaxed its requirements for evaluating the safety and effectiveness of their vaccines.

According to executives, it is “understandable” that the public has concerns, stressing that they will need to work to establish trust.

“Vaccine hesitancy is probably one of the greatest challenges for public health that America faces,” John Young, Pfizer’s chief business officer, said at the Congress on July 21. “All of us need to play a role, should we be successful in this mission, that there’s confidence in the safety and effectiveness of our vaccines based on data, based on confidence the FDA will only approve a vaccine if it’s safe and effective.”