Pfizer and BioNTech said Jan. 25 they have launched a clinical study evaluating the safety and efficacy of an omicron-specific COVID-19 vaccine candidate.
The study will include up to 1,420 participants ages 18-55 across three cohorts, according to a news release.
The first cohort includes 615 participants who received two doses of Pfizer's original COVID-19 vaccine 90-180 days prior to enrollment. They will receive one or two doses of the omicron-specific vaccine.
The second cohort includes 600 participants who received three doses of Pfizer's original COVID-19 vaccine 90-180 days prior to enrollment. They will receive one dose of the original vaccine or the omicron-specific vaccine.
The third cohort includes 205 unvaccinated participants. They will receive three doses of the omicron-specific vaccine.
Read Pfizer's release here.