US health officials' decision to shorten the recommended COVID-19 isolation and quarantine period from 10 days to five is drawing a mixed reaction. The guidance has raised questions about how it was crafted and why it was changed amid a wintertime spike in cases, one driven largely by the omicron variant. Monday's action by the Centers for Disease Control and Prevention halved the recommended isolation time for those infected with the coronavirus without symptoms. Also on Monday, Pr...