A number of states immediately embraced new guidelines from the CDC 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 policy is safe or even workable, given that it essentially leaves it up to people to do the right thing. Business groups and others warned that employees at stores and other businesses could be left exposed to the virus from customers and could be forced into the unwanted role of “vaccination police.”