The vaccine, being developed in collaboration with BioNTech (NSDQ:BNTX), was tested in mouse and non-human primate models. In the non-human primate study, the BNT162b2 mRNA-based vaccine candidate protected rhesus macaques against SARS-CoV-2 infection, according to a news release.
In a viral infection model, macaques received two injections with 100 µg of the vaccine candidate and macaques that received saline control injections were challenged 55 days after the second immunization with a high viral inoculum of about 1 million plaque-forming units of SARS-CoV-2. Immunization with BNT162b2 reduced viral infection with no viral RNA detected in the lower respiratory tract of the immunized animals, while the control group demonstrated evidence of viral RNA.
Among the anti-viral effects demonstrated by the vaccine were concomitant high neutralizing antibody titers and a TH1-biased cellular response in both rhesus macaques and mice. BNT162b2 also induced potent SARS-CoV-2 neutralizing antibodies in the vaccinated macaques, plus viral antigen-specific CD4+ and CD8+ T cells.
“Collectively, these preclinical results, combined with our clinical data collected to date, continue to support the promise and validity of our mRNA-based vaccine program against SARS-CoV-2 and selection of the BNT162b2 candidate, which we believe has the potential to prevent many millions of COVID-19 cases,” Pfizer senior VP & head of vaccine R&D Kathrin Jansen said in the release. “We are encouraged by the data thus far and confident in our progress towards developing a safe and effective vaccine candidate to help address this current pandemic.”
“The data we have shared today include the characterization of our lead candidate BNT162b2, as well as key animal studies that were the basis for our clinical programs. They have enabled us to advance BNT162b2 into Phase 3 evaluation,” added BioNTech founder & CEO Dr. Ugur Sahin. “This is another development milestone for providing a safe and effective potential vaccine to the global community to help end this pandemic.”
Pfizer and BioNTech have now commenced a global (excluding China) Phase II/III safety and efficacy clinical trial for the vaccine candidate, with over 25,000 participants between 18 and 85 years old enrolled in the U.S., Argentina and Brazil. Enrollment is expected to expand to Germany, Turkey and South Africa.
The companies said in the release that they are on track to seek regulatory review for BNT162b2 as early as October 2020, with plans to supply up to 100 million doses worldwide by the end of 2020 and 1.3 billion doses by the end of 2021.
In July, the U.S. Dept. of Health and Human Services and the U.S. Defense Dept. agreed to a large-scale production and U.S. delivery deal once Pfizer’s vaccine is successfully manufactured and approved. In addition to the 100 million doses initially agreed upon, the U.S. government will be able to acquire an additional 500 million doses.