The MMR vaccine is a combination vaccine that contains components that protect against three different germs — measles, mumps, and rubella. The MMR vaccine has not always been a combination vaccine. At one point, the vaccines for measles, mumps, and rubella were three separate vaccines. These three individual vaccines were all invented in the same decade — measles vaccine in 1963, mumps vaccine in 1967, and the rubella vaccine in 1969. Since all three vaccines were made from live viruses, it was not difficult to combine them into one shot to reduce the number of injections children get. In 1971, the MMR combination vaccine was introduced in the United States by the Merck pharmaceutical company. Merck still manufactures the vast majority of the MMR vaccine used in the United States today.

When the MMR vaccine first became available, doctors only recommended one dose of the MMR vaccine at age twelve months, but this vaccine regimen only protected 95 percent of all children from these infections. Even though 95 percent may sound really good to you, it was not good enough to prevent some children from dying of measles. The American Academy of Pediatrics decided in 1989 to recommend a second booster shot for the MMR vaccine at age four year, which is right before many children first enter school. This second dose of vaccine boosts the effectiveness of the vaccine to more than 99 percent.

The MMR vaccine can be administered at the same time as other vaccines. However, if another vaccine containing live virus is not given at the same time as the MMR vaccine, the other live-virus vaccine (frequently the chickenpox vaccine) must be postponed for at least twenty-eight days after the MMR vaccine. If two vaccines containing live virus are given too close together, they may interfere with each other and can cancel out each other's effect.

Ever since the introduction of the second MMR vaccine booster, measles infection has become relatively rare in America. Most parents have never seen a child with measles, due to the drastic reduction in the chance of catching this highly contagious infection.

Many adults have never had measles or received the measles vaccine. If you were born after 1956 and have never had the measles vaccine, you should talk to your doctor to see whether you should get vaccinated against measles. If you do not remember whether you had the measles vaccine or cannot find any record of your immunization, there is a blood test that can be done to find out whether you have been exposed to measles. If there is no evidence of immunity against measles, you should seriously consider getting the measles vaccine to protect yourself.

Most people mistakenly believe that they have had the measles infection in the past when in fact they have not. Many other viral infections can mimic the measles infection. So simply having a recollection of a measles infection does not prove that one is immune to measles. Immunity can only be proven with an immunization documentation in the medical record or with a blood test.

Adults who are returning to school to get their college degree may be required to show proof of immunity against measles. You can either provide a copy of your immunization record or you can have a blood test done to demonstrate that you have the antibody against the measles virus. If you have never had the vaccine or the infection, you would need two doses of the MMR vaccine, administered at least four weeks apart.