COVID-19 levels are surging in the US after a long lull [Video]

After a relatively slow start to the respiratory virus season, COVID-19 levels in the United States began ramping up just ahead of the winter holidays.Video above: Experts offer tips on staying healthy for the holidaysIn previous years, COVID-19 levels have typically started to rise in early November and reach their seasonal peak by the end of December. But this year, levels were nearly the lowest they’ve ever been through October and all of November, according to wastewater surveillance data from the U.S. Centers for Disease Control and Prevention.Trends started to shift in early December, though, with levels rising from low to high by the middle of the month. In the week ending on Dec. 21, there was nearly three times as much COVID-19 circulating in the U.S. than there was during the week ending Dec. 7, CDC data shows.This surge happened in all regions of the country, but there has …