Pfizer and BioNTech have started a clinical trial to evaluate the safety and effectiveness of an Omicron-specific COVID-19 vaccine candidate.
The companies announced the study on Tuesday, saying the goal is to enroll up to 1,420 healthy adults between the ages of 18 and 55.
The variant-specific vaccine will be administered as a two-dose primary series and as a booster dose, Pfizer said.
"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 to towards this goal," Kathrin Jansen, Senior Vice President and Head of Vaccine Research and Development at Pfizer, said in a statement.
Study participants will be separated into three groups.
The first group includes people who have received two doses of the current Pfizer COVID-19 vaccine 90 to 180 days before the study; these participants will receive one or two doses of the Omicron-based vaccine.
The second group includes people who have received two doses and a booster of the Pfizer COVID-19 vaccine 90 to 180 days before the study; these participants will receive one dose of the current Pfizer COVID-19 vaccine or the Omicron-based vaccine.
The third group includes people who have not received a COVID-19 vaccine yet; these participants will receive three doses of the Omicron-based vaccine.
The drugmakers said the study is part of their ongoing efforts to address Omicron and determine the potential need for variant-based vaccines.
"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," Jansen said.
Clinical and real-world data continue to find people who are vaccinated, particularly those that have received a booster, maintain a high level of protection against Omicron, especially against severe disease and hospitalization.
"This study is part of our science-based approach to develop a variant-based vaccine that achieves a similar level of protection against Omicron as it did with earlier variants but with longer duration of protection," Ugur Sahin, CEO and co-founder of BioNTech, said in a statement.
The drugmakers previously announced that they expect to produce four billion doses of the Pfizer-BioNTech COVID-19 vaccine in 2022. The companies do not expect that number to change if an Omicron-specific vaccine is required.
Omicron currently accounts for virtually all new coronavirus cases in the U.S., according to the latest data from the Centers for Disease Control and Prevention.