European stock markets and oil prices jumped on the news after the joint statement was released on Monday.
"The first set of results from our phase 3 Covid-19 vaccine trial provides the initial evidence of our vaccine's ability to prevent Covid-19," said Pfizer chairman and CEO Albert Bourla.
According to preliminary findings, protection in patients was achieved seven days after the second of two doses, and 28 days after the first.
"We are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis," Bourla said.
"We are reaching this critical milestone in our vaccine development program at a time when the world needs it most."
UPDATE: We are proud to announce, along with @BioNTech_Group, that our mRNA-based #vaccine candidate has, at an interim analysis, demonstrated initial evidence of efficacy against #COVID19 in participants without prior evidence of SARS-CoV-2 infection.
— Pfizer Inc. (@pfizer) November 9, 2020
Across much of the globe, Covid-19 infections rates are hitting record highs, with hospital intensive care units filling up and death tolls mounting.
Based on supply projections, the companies said they expect to supply up to 50 million vaccine doses globally in 2020, and up to 1.3 billion doses in 2021.
US biotech firm Moderna, several state-run Chinese labs, and a European project led by the University of Oxford and AstraZeneca are thought to be closing in on potentially viable vaccines.
Two Russian Covid-19 vaccines have been registered even before clinical trials were completed, but have not been widely accepted outside of Russia.
The phase 3 clinical trial -- the final stage -- of the new vaccine, BNT162b2, began in late July and has enrolled 43,538 participants to date, 90 percent of whom have received a second dose of the vaccine candidate as of 8 November.
Pfizer said it is gathering two months of safety data following the final dose -- a requirement of the US Food and Drug Administration (FDA) -- to qualify for Emergency Use Authorization, which it expects by the third week in November.
42 candidate vaccines
"We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks," Bourla said.
Pfizer and BioNTech plan to submit data from the full phase 3 trial for scientific peer-review publication.
As of mid-October, the World Health Organization (WHO) has identified 42 candidate vaccines at the stage of clinical trials, up from 11 in mid-June.
Ten of them were at the most advanced phase 3 stage, in which a vaccine's effectiveness is tested on a large scale, generally tens of thousands of people across several continents.
(with AFP)
