The Australian Border Force said the top-ranked tennis player "failed to provide appropriate evidence to meet the entry requirements to Australia, and his visa has been subsequently cancelled."

Hong Kong authorities announced a two-week ban on flights from eight countries and held 2,500 passengers on a cruise ship for coronavirus testing as the city attempted to stem an omicron outbreak.

The omicron variant is outpacing the government's ability to make and execute clear pandemic public policy.

In the face of rising COVID-19 cases, Dr. Bob Wachter of the University of California, San Francisco, offers reasons to be hopeful about the pandemic's outlook in the months ahead.