- Pfizer and BioNTech are starting clinical trials for an Omicron-specific COVID-19 vaccine on adults.
- The study will be evaluated in 1,400 adults aged 18-55, the two companies announced on Tuesday.
- Pfizer's chief scientific officer said earlier in January that the shot would be ready in March.
Pfizer and BioNTech are starting clinical trials for an Omicron-specific coronavirus vaccine on adults, the two companies announced on Tuesday.
The study, which will measure the "safety, tolerability and immunogenicity" of a COVID-19 vaccine specifically tailored to the highly transmissible Omicron variant, will be evaluated in 1,400 adults ages 18 to 55.
"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's Senior Vice President Kathrin Jansen said in a statement.
Mikael Dolsten, Pfizer's chief scientific officer, told Insider's Andrew Dunn earlier this month that the shot would be ready by late March.
But it was unclear whether the Omicron-specific shot would be needed, Dolsten said at the time.
Centers for Disease Control and Prevention data shows that two-shot vaccine protection is less effective against Omicron than it is against the previously-dominant Delta variant — and immunity against both strains wanes just six months after an individual receives a second dose.
For the Omicron variant, the booster shot's effectiveness at preventing hospitalization sits at 90%, up from 57% effectiveness just 26 weeks after receiving just the second dose, Insider previously reported.
"I don't know if we will need it. I don't know if it will be used, but it will be ready." Pfizer CEO Albert Bourla told CNBC earlier in January.
The two companies' announcement comes as the US is averaging nearly 664,000 daily new COVID-19 cases, according to the latest CDC data, down from a mid-January peak of around 800,000 cases.
According to the latest CDC estimates, the highly transmissible Omicron variant accounts for over 99% of all COVID-19 infections in the country.