Clues to Omicron Variant’s U.S. Spread Include Test Samples, Sewage - The Wall Street Journal

Researchers are racing to determine how widespread the Omicron variant might be across the U.S., scouring Covid-19 test samples and in some cases even examining wastewater.

Federal regulators said Sunday that cases have been identified in 16 states and that the Food and Drug Administration is in conversations about streamlining authorization for revamped vaccines if necessary.

Covid-19 surveillance is more robust in the U.S.