Albert Bourla, the CEO of Pfizer (NYSE:PFE), raised a lot of eyebrows on Thursday morning during a press briefing with biopharmaceutical industry executives leading efforts to develop vaccines and treatments to help mitigate the COVID-19 pandemic.

Speaking off the cuff, Bourla said the company expects interim results from an ongoing pivotal trial by the end of October. He was also careful to bookend his statement with some important caveats concerning the coronavirus vaccine Pfizer's developing in partnership with BioNTech (NASDAQ:BNTX).

A man with fingers crossed

Image source: Getty Images.

That vaccine candidate, BNT162b2, uses a strand of messenger RNA (mRNA) to coax human cells into producing proteins that resemble SARS-CoV-2 so our immune systems can immediately recognize the real thing as a threat, if necessary. As of Aug. 20, more than 11,000 participants had enrolled in a pivotal trial expected to ultimately involve 30,000 people in more than 100 study locations spread throughout the U.S.

The BNT162 program began with four closely related vaccine candidates, all of which began the first portion of an enormous pivotal in late July. Results from an earlier phase 1 trial reported in August led the partners to select BNT162b2 as the lead candidate.

The partners were encouraged by blood samples that contained antibodies that should prevent SARS-CoV-2 from entering host cells. Seven days after the second dose of BNT162b2 patients were exhibited concentrations of SARS-CoV-2-neutralizing antibodies at concentrations 3.8 times higher than average concentrations of COVID-19 patients that fought off the infection.

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