It's safe for families to visit Disneyland, as long as everyone is fully vaccinated, one expert says. But families with infants or people who have not been immunized should consider staying away from venues where measles has been identified, Dr. Gil Chaves told NBC News. The potentially deadly virus has already infected at least 70 people in six states — including at Disneyland in California — and in Mexico. Since Disneyland constantly hosts visitors from around the world, the number of cases is expected to increase, Chavez says.