Pfizer-BioNTech omicron-adapted COVID vaccines demonstrate high immune response

"As we've said since the early days of the pandemic, we will follow the science and adapt our own approaches as needed to help address COVID-19 as the virus evolves," said Albert Bourla, Chairman and Chief Executive Officer, Pfizer. "Based on these data, we believe we have two very strong Omicron-adapted candidates that elicit a substantially higher immune response against Omicron than we've seen to date. We look forward to discussing these data with the scientific community and health authorities so we may rapidly introduce an Omicron-adapted booster as soon as possible if authorized by regulators."

"The data show the ability of our monovalent and bivalent Omicron-adapted vaccine candidates to significantly improve variant-specific antibody neutralization responses," said Prof. Ugur Sahin, M.D., CEO and Co-founder of BioNTech. "Omicron has newly evolving sublineages that have outcompeted BA.1 and exhibit a trend of increasing potential for immune escape. We will therefore remain vigilant and are prepared to rapidly adapt our Omicron-adapted vaccine candidates to emerging sublineages if epidemiological and laboratory data suggest."

The Omicron adapted vaccine candidates (30 µg and 60 µg) studied in the Phase 2/3 trial in 1,234 participants 56 years of age and older elicited substantially higher neutralizing antibody responses against Omicron BA.1 when compared to the companies' current COVID-19 vaccine. The pre-specified criterion for superiority was measured by the ratio of neutralizing geometric mean titers (GMR) with the lower bound of the 95% confidence interval >1. The geometric mean ratios (GMRs) for the monovalent 30 µg and 60 µg vaccines compared to the current COVID-19 vaccine were 2.23 (95% CI: 1.65, 3.00) and 3.15 (95% CI: 2.38, 4.16), respectively. The GMRs for the bivalent 30 µg and 60 µg vaccines compared to the current COVID-19 vaccine were 1.56 (95% CI: 1.17, 2.08) and 1.97 (95% CI: 1.45, 2.68), respectively. The monovalent Omicron-adapted vaccine 30 µg and 60 µg achieved a lower bound 95% confidence interval for GMR of >1.5, consistent with the regulatory requirement of super superiority. Demonstration of superiority against Omicron and safety are regulatory requirements for potential emergency use authorization of a variant-adapted vaccine.

One month after administration, a booster dose of the Omicron-adapted monovalent candidates (30 µg and 60 µg) increased neutralizing geometric mean titers (GMT) against Omicron BA.1 13.5 and 19.6-fold above pre-booster dose levels, while a booster dose of the Omicron-adapted bivalent candidates conferred a 9.1 and 10.9-fold increase in neutralizing GMTs against Omicron BA.1. Both Omicron-adapted vaccine candidates were well-tolerated in participants who received one or the other Omicron-adapted vaccine.

In a SARS-CoV-2 live virus neutralization assay tested on sera from participants over 56 years of age and older, sera efficiently neutralized BA.4/BA.5 with titers approximately 3-fold lower than BA.1.

"Pfizer and BioNTech will continue to collect additional study data on Omicron BA.4/BA.5 over the coming weeks. These results are being shared with the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) in advance of upcoming discussions with the FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC) on June 28 and with the International Coalition of Medicines Regulatory Authorities (ICMRA) on June 30. The companies have also submitted additional data from their ongoing COVID-19 booster studies, including data on an additional dose of their current COVID-19 vaccine and Beta candidate, to further demonstrate the flexibility and potential benefit of mRNA-based vaccines," the release stated.

The Pfizer-BioNTech COVID-19 Vaccine, which is based on BioNTech's proprietary mRNA technology, was developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorization Holder in the United States, the European Union, the United Kingdom, Canada and other countries, and the holder of emergency use authorizations or equivalents in the United States (jointly with Pfizer) and other countries. Submissions to pursue regulatory approvals in those countries where emergency use authorizations or equivalent were initially granted are planned.