
The United Kingdom has become the first country to approve vaccine boosters designed to target the omicron variant of COVID-19, paving the way for Brits to receive their shots in early fall.
The Moderna shot approved in the U.K. is "bivalent," meaning it's a mix of two versions of the vaccine: Half is targeted at the original strain of COVID-19, and half is a new formulation designed to fight the original omicron variant, also known as BA.1.