Some health officials say they are concerned about a decline in COVID-19 testing.

The COVID Tracking Project shows test rates have dipped by a quarter since mid-January.

The CDC says those tests are critical to controlling the pandemic, even as vaccinations are getting underway.

The agency points to case numbers that are plateauing and coronavirus variants that are spreading.

The CDC now warns against gatherings for this St. Patrick's Day.

Traveling can also increase the risk of spreading the virus.