Pfizer and BioNTech have begun a clinical trial for their Omicron-specific Covid-19 vaccine candidate, they announced in a news release on Tuesday.

The study will evaluate the vaccine for safety, tolerability and the level of the immune response, as both a primary series and a booster dose, in up to 1,420 healthy adults ages 18 to 55.

The study is broken up into three groups:
Participants in the first cohort have received two doses of the current Pfizer Covid-19 vaccine at least 90 to 180 daysbefore the study. They will receive one or two doses of the Omicron-specific vaccine. After the Omicron wave, here's what experts say could come next in 2022.

Participants in the second cohort have received three doses of the current Pfizer Covid-19 vaccine at least 90 to 180 days prior to the study. They will receive one dose of the current Pfizer Covid-19 vaccine or the Omicron-specific vaccine.
Participants in the third cohort have not received any Covid-19 vaccine. They will receive three doses of the Omicron-specific vaccine.

The Omicron-specific vaccine will be administered as a 30-microgram dose, the same as the current vaccine.
"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," Pfizer Senior Vice President and Head of Vaccine Research and Development Kathrin Jansen said in the release.

For Full story

https://edition.cnn.com/2022/01/25/health/pfizer-biontech-omicron-vaccine-trial/index.html