The total number of reported coronavirus cases in the United States marched toward 50 million Tuesday, as the omicron variant — which experts worry may prove especially contagious — has spread to much of the country.

Public health experts say the overwhelming majority of the nation’s coronavirus cases are still caused by the highly transmissible delta variant, which has led to some of the worst spikes of the pandemic. The United States has tallied more than 49 million coronavirus cases and more than 787,000 deaths, according to Washington Post tracking.
Here’s what to know
  • Federal health authorities see a New York City anime convention as a test case for how omicron behaves.
  • Anthony S. Fauci, the nation’s top infectious-disease expert, said the omicron variant appears to cause less severe illness — though he cautioned that the available data remains preliminary and anecdotal.
  • Google and Uber are delaying their office returns.