Pfizer Inc. said it is starting a study of a COVID-19 vaccine that targets the omicron variant, exploring its use in previously vaccinated younger and middle-aged adults as well as those who haven’t received another coronavirus shot.
The New York-based drugmaker and its German partner, BioNTech SE, said in a statement on Tuesday that they had enrolled the first participants in a 1,420-person clinical trial that will evaluate the shot’s ability to prompt an immune response in healthy adults age 18 to 55. The study will also examine the shot’s safety and potential side effects.
The trial will examine the new formulation as an initial two-dose regimen and as a booster dose, the companies said.
Kathrin Jansen, Pfizer’s head of vaccine research and development, said that the company is making preparations in case the protection offered by current COVID-19 booster shots against severe disease and hospitalizations wanes.
“Staying vigilant against the virus requires us to identify new approaches for people to maintain a high level of protection,” Jansen said in the statement. “We believe developing and investigating variant-based vaccines, like this one, are essential in our efforts towards this goal.”
Three different groups will be studied in the trial. The first group, made up of 615 participants who had received two doses of the original Pfizer-BioNTech vaccine, will get one or two doses of the omicron shot. Another group of 600 people who got three doses of the initial regimen will get an additional shot of the same formulation or the omicron vaccine. And a third group of 205 participants who have never been vaccinated will get three doses of the omicron shot.
Pfizer and BioNTech will draw some trial participants from their late-stage COVID-19 booster study for the new trial.
“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 longer duration of protection,” said Ugur Sahin, co-founder and chief executive officer of BioNTech.
Earlier this month, Pfizer CEO Albert Bourla said that the companies were also developing a hybrid vaccine that would combine its original shot with an omicron-fighting formulation. Speaking at the JPMorgan Healthcare Conference, Bourla said that they would determine which is best-suited to move forward by March.
Pfizer and BioNTech said Tuesday that they will launch additional multiarm studies in the first quarter evaluating their current vaccine, the omicron-specific shot, and a combination of the two at varying dose levels.
