The changes come amid a recent surge in cases spurred by the omicron variant and concerns about staffing shortages at hospitals, airlines and businesses across the country. Research has suggested omicron, while more infectious, causes milder illness. CDC officials say the new guidance is in keeping with growing evidence that people with the coronavirus are most infectious in the two days before and three days after symptoms develop. CDC Director Rochelle Walensky said the country is about to see a lot of omicron cases. “Not all of those cases are going to be severe. In fact many are going to be asymptomatic,” she told The Associated Press on Monday. “We want to make sure there is a mechanism by which we can safely continue to keep society functioning while following the science.”