All coverage
Pfizer and BioNTech launch trial of Omicron-targeted COVID vaccine
By Michael Erman & Ludwig Burger
Omicron variant: Pfizer starts clinical trial for modified Covid vaccine
By Berkeley Lovelace & Berkeley Lovelace Jr.
As Pfizer and BioNTech begin clinical trial of Omicron-based vaccine, timeline to authorization is unclear
By Matthew Herper
Moderna starts trial for Omicron-specific booster shot
By Devika Syamnath, Sherry Jacob-Phillips & Amruta Khandekar