Richard Arnold: Concern about potential fourth wave of Covid-19 in US

More than 104.2 million people, or 31.4% of the U.S. population, have received at least one dose of a coronavirus vaccine, according to the Centers for Disease Control and Prevention. Some 59.8 million people, or 18% of the population, have completed their vaccination.The seven-day rolling average for daily new cases in the U.S. increased over the past two weeks from 54,471 on March 19 to 64,616 on Friday, according to Johns Hopkins University.The seven-day rolling average for daily new deaths in the U.S. decreased over the past two weeks decreased from 1,160 on March 19 to 847 on Friday, according to Johns Hopkins University.See omnystudio.com/listener for privacy information.