The US Centers for Disease Control and Prevention (CDC) has reported that measles outbreaks have occurred in New York City, California and Arizona in 2008, and additional cases have been confirmed in Michigan, Wisconsin, Hawaii, New York State, Pennsylvania, Illinois and Virginia (CDC Health Advisory, May 1, 2008). To date, 63 of the 64 infected patients were unvaccinated, and 54 of the cases were associated with importation of the disease. Both measles infection and vaccination (2 doses at least 28 days apart, with the first dose no earlier than 12 months of age) generally provide lifelong immunity. Patients >12 months old with no evidence of immunity (not born before 1957, no convincing history of clinical measles, no documentation of vaccination, and no laboratory evidence of immunity) should be vaccinated with MMR or monovalent measles vaccine. In an outbreak, children 6-12 months old can also be vaccinated, but they will still need 2 subsequent doses after the age of 12 months to be fully immunized.1 Contraindications to the attenuated livevirus vaccine include pregnancy, immunosuppressive therapy, leukemia or lymphoma, and congenital or acquired immunodeficiency. Transient fever and/or rash can occur after vaccination.