Study Shows Positive Data on Pair of Omicron-Adapted COVID-19 Vaccine Candidates

A booster dose of both Omicron-adapted vaccine candidates elicited a substantially higher immune response against Omicron BA.1.

Pfizer and BioNTech announced positive data evaluating the safety, tolerability, and immunogenicity of 2 Omicron-adapted COVID-19 vaccine candidates, one of which is monovalent and the other being bivalent, combining the Pfizer-BioNTech COVID-19 vaccine and a vaccine candidate targeting the spike protein of the Omicron BA.1 variant of concern.

Data from a phase 2/3 trial demonstrated that a booster dose of both Omicron-adapted vaccine candidates elicited a substantially higher immune response against Omicron BA.1 compared to the current COVID-19 vaccine from the company. The response was seen at 2 investigational dose levels of 30 µg and 60 µg.

“Based on these data, we believe we have 2 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,” Albert Bourla, chairman and CEO of Pfizer, said in a statement.

Investigators included 1234 individuals 56 years of age or older. The pre-specified criterion for superiority of the vaccine candidates was measured by the ratio of neutralizing geometric mean titers (GMR) with the lower bound of the 95% confidence interval being greater than 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 and 3.15, respectively. For the bivalent vaccines compared to the current COVID-19 vaccine, the GMRs were 1.56 and 1.97, respectively.

The monovalent vaccine achieved a lower bound 95% interval for GMR of greater than 1.5, which is consistent with regulatory requirement of super superiority.

The demonstration of superiority against the Omicron variant and safety regulatory requirements for potential emergency use authorization of a variant-adapted vaccine.

“The data show the ability of our monovalent and bivalent Omicron-adapted vaccine candidates to significantly improve variant-specific antibody neutralization responses,” Ugur Sahin, MD, CEO, and co-founder of BioNTech, said in the statement.

“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,” Sahin said.

One month after administration, a booster dose of the monovalent candidates at the 30 µg and 60 µg strengths was found to increase neutralizing GMT against Omicron BA.1 13.5- and 19.6-fold above pre-booster dose levels, respectively. For the bivalent candidates, they increased GMTs by 9.1- and 10.9-fold against the Omicron BA.1.

Furthermore, both Omicron-adapted vaccine candidates were well-tolerated in individuals who received either vaccine.

Pfizer and BioNTech will continue to collect additional study data on Omicron BA.4 and BA.5 over the coming weeks.

The companies have also submitted additional data from their ongoing COVID-19 booster studies, including data on an additional dose of the current and Beta vaccines, to demonstrate the flexibility and potential value of mRNA-based vaccines.

Reference

Pfizer and BioNTech announce Omicron-adapted COVID-19 vaccine candidates demonstrate high immune response against Omicron. Pfizer. News release. June 25, 2022. June 29, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-announce-omicron-adapted-covid-19