Newly reported coronavirus infections in the United States continued their steep drop, with about 56,000 new cases reported Monday, although that number is probably artificially low due to the holiday. However, the seven-day average, considered a more reliable measure, has dipped below 90,000 a day for the first time since early November.

Scientists have been split about the reasons for the drop, citing increased vaccinations, decreased testing and the seasonal patterns of these kinds of viruses, whose transmission rates decline as the winter goes on. Others have suggested it’s because people are getting better at following social distancing restrictions.

On the increase, however, are cases of the more contagious variant first identified in Britain, which have doubled in the United States every 10 days, according to the Centers for Disease Control and Prevention. The instances are still low, but climbing. Only 293 cases were reported in late January. By Feb. 4, there were 611, and the number now stands at 1,168.

Here are some significant developments:
  • New York Gov. Andrew M. Cuomo (D) for the first time Monday acknowledged a lack of transparency in his administration’s initial reporting of coronavirus deaths in New York nursing homes, but he stopped short of an apology.
  • Less than a year after being crippled with hundreds of cases, the aircraft carrier USS Theodore Roosevelt has announced three new positive tests for coronavirus onboard.
  • Britain’s fast-running coronavirus vaccination campaign appears to have hit its early target, offering a first dose to 15 million elderly people and health-care workers by Monday.
  • Nearly a year into the pandemic, Americans are increasingly turning to more extremist beliefs marked by a wholesale distrust in authorities — a historical pattern for pandemics since ancient times.
  • The World Health Organization has approved the AstraZeneca-Oxford University vaccine, opening the way for millions of doses of the inexpensive vaccine to be shipped to lower-income countries as part of a U.N.-backed effort to stop the pandemic.
  • More than 485,000 people have died of the coronavirus since it was first identified in the United States, and over 27 million cases have been reported.