(By Dr. William Petri, professor of medicine) In December 2021, the U.S. Centers for Disease Control and Prevention updated its guidelines for how long people should isolate following a COVID-19 infection. The agency shortened the isolation from 10 days to five, followed by five days of wearing a mask for those no longer symptomatic. The change came during the height of the omicron variant’s surge and related staffing shortages at hospitals, schools and businesses. Some critics suspected that the move was more practically motivated than science-based to allow workers, especially health care an...