Pfizer and BioNTech announce plans to test omicron-specific COVID-19 vaccine in adult trials

Vaccine makers Pfizer and BioNTech announced plans early Tuesday to test an omicron-specific COVID-19 vaccine in people. 

The companies will run three simultaneous trials in adults ages 18-55 to determine if an omicron-specific vaccine is more effective than current shots.

The existing vaccine was developed to target the original or "ancestral" strain of COVID-19. While three shots appear to provide some protection against omicron, the vaccine, called Comirnaty, is not as effective as it was against earlier strains.

“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 a) longer duration of protection,” BioNTech CEO and co-founder Uğur Şahin said in a statement.

In the first trial, 615 people who received two doses of Comirnaty at least 3-6 months ago will receive one or two shots of the omicron-specific vaccine.

In the second trial, which will include 600 volunteers, those who received three doses at least 3-6 months ago will receive one dose of the current vaccine or one dose of the omicron-specific version.

And in a third trial, 200 participants who have never been vaccinated will receive three doses of the omicron-specific vaccine.