A number of states have embraced new federal guidelines that say fully vaccinated people no longer need to wear masks indoors or out in most situations. But other states and some businesses are taking a wait-and-see attitude amid questions of whether the new advice from the Centers for Disease Control and Prevention is safe or even workable since it essentially leaves it up to people to do the right thing. Labor groups and others warned that employees at stores and other businesses could be forced into the unwanted role of “vaccination police.” The states that announced plants to fall in line with the CDC guidance span the country.