Measles can cause serious illness. People who were born after 1956 should check their immunization status before traveling to countries where measles is still common.

A person is considered to be immune if he or she has been diagnosed with measles by a doctor in the past, has received the recommended doses of the measles, mumps, and rubella (MMR) vaccine or the measles, mumps, rubella, and varicella (MMRV) vaccine, or has lab evidence of measles immunity. Some people who received an early version of the measles vaccine may not be fully protected. If these people are exposed to measles, they may be more likely to get a rare but severe form of the disease. If you are not immune to measles, check with your doctor or local immunization clinic to see whether you should receive the vaccine before you travel.

Infants and young children who have not yet received the measles immunizations may need to be immunized early or have their immunization schedule adjusted. For more information, see the topic Immunizations.