Rob Stein

The virus, known as BA.2, is a strain of the highly contagious omicron variant that appears to spread even more easily — about 30% more easily.

Part of the problem is the conflicting, ever-changing advice people are hearing from different political leaders.

zer-BioNTech is expected to file a submission for emergency use to the Food and Drug Administration for a vaccine regimen designed for use in children aged six months to five years.

The analysis projects the omicron wave will infect more than 400,000 people a day in the U.S. when it crests in about six weeks. That's far more than the 250,000 people who caught the virus every day at the peak of last winter's surge.

The Moderna vaccine's ability to shield against infection drops sharply when tested on the omicron variant. But getting a booster pumps the protection back up again, new research suggests.

What's the U.S. doing to watch out for the omicron variant? Here's the work underway and the challenges that experts say may slow down the country's efforts.

As the delta variant causes more vaccinated people to get "breakthrough infections," concerns are rising that even the vaccinated could develop long COVID symptoms in rare cases.