Measles is a highly contagious virus characterized by fever, rash, and often pneumonia. It has been virtually eliminated from the United States through widespread vaccination of children at age 15 months. This immunization occurs in the form of the MMR immunization (Measles, Mumps, Rubella) and is performed as a 2-shot series.
You are considered immune to measles and unable to be reinfected if:
1. Your were born before 1957. (Virtually all people born before 1957 were exposed to measles as it was prevalent in all areas of the counter, and occurred in epidemics in many years prior to that date.)
2. You had documented measles. (Many people do not recall such a history, so this is often not a helpful marker. Still, some people are aware of having been definitely ill with measles.)
3. You were born after 1967 and received the two shots of MMR (live) vaccine. (Virtually all people who lived in the US, and were born after 1967 were given the MMR vaccine in the appropriate interval and dosing, unless they know that their family was trying to avoid immunization.)
4. You have had a blood test that is positive for Rubeola (measles) IgG. (This proves immunity to measles.)
Anyone born in the US between 1958 and 1967 likely received the inactivated (dead) measles vaccine, and this was known to be less effective than the modern live MMR. They are likely to be immune to measles, but to prove immunity, a measles (Rubeola) IgG blood test can be done to be certain. These people likely are safe, but blood testing is sensible if concerned.