Pfizer, BioNTech to Evaluate Omicron-Based COVID-19 Vaccine in Adults 18 to 55 Years of Age

A clinical study has been initiated to evaluate the safety, tolerability, and immunogenicity of an omicron-based vaccine candidate in healthy adults between 18 and 55 years of age, according to a Pfizer press release.

The study will have 3 cohorts examining different regimens of the current Pfizer-BioNTech COVID-19 vaccine or an omicron-based vaccine and will use participants from the phase 3 COVID-19 booster study.

“While current research and real-world data show that boosters continue to provide a high level of protection against severe disease and hospitalization with omicron, we recognize the need to be prepared in the event this protection wanes over time and to potentially help address omicron and new variants in the future,” said Kathrin U. Jansen, PhD, senior vice president and head of Vaccine Research & Development at Pfizer, in the press release. “Staying vigilant against the virus requires us to identify new approaches for people to maintain a high level of protection, and we believe developing and investigating variant-based vaccines, like this one, are essential in our efforts towards this goal.”

Earlier this month, Pfizer and BioNTech SE announced the results from 2 laboratory studies showing that 3 doses of the Pfizer-BioNTech COVID-19 vaccine elicited antibodies that neutralize the omicron variant. Both data sets confirm previously announced initial study results showing that serum antibodies induced by the Pfizer vaccine neutralized the SARS-CoV-2 omicron variant after immunization with 3 doses.

By comparison, sera from individuals who received 2 doses of the COVID-19 vaccine showed limited neutralization titers against the omicron variant in both data sets, indicating that 2 doses of the vaccine may not be sufficient to protect against infection with the new variant.

The new study will evaluate up to 1420 participants across the 3 cohorts:

• Cohort 1: Participants received 2 doses of the current Pfizer-BioNTech COVID-19 vaccine 90 to 180 days prior to enrollment and 1 or 2 doses of the omicron-based vaccine.
• Cohort 2: Participants received 3 doses of the current Pfizer-BioNTech COVID-19 vaccine 90 to 180 days prior to enrollment and 1 dose of the current Pfizer-BioNTech COVID-19 vaccine or the omicron-based vaccine.
• Cohort 3: Vaccine-naïve participants will receive 3 doses of the omicron-based vaccine.

REFERENCE

Pfizer and BioNTech initiate study to evaluate omicron-based COVID-19 vaccine in adults 18 to 55 years of age. Pfizer. January 25, 2022. Accessed January 26, 2022. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-initiate-study-evaluate-omicron-based