When is it appropriate to use MMR vaccine for measles post-exposure prophylaxis?

MMR vaccine given within 72 hours of initial measles exposure can reduce the risk of getting sick or reduce the severity of symptoms. Another option for exposed, measles-susceptible individuals at high risk of complications who cannot be vaccinated is to give immunoglobulin (IG) within six days of exposure. Do not administer MMR vaccine and IG simultaneously, as the IG invalidates the vaccine.

Information on post-exposure prophylaxis for measles can be found in the 2013 ACIP guidance at www.cdc.gov/mmwr/pdf/rr/rr6204.pdf, page 24.