Questions & Answers
Measles - The Vaccine
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  1. What kind of vaccine is given to prevent measles?

    Most people receive measles vaccine as part of a combination vaccine known as M-M-R II® which also protects against two other viruses – mumps and rubella. Another option is a vaccine called Proquad® which provides protection against measles, mumps, rubella and varicella (chicken pox) in one shot. A vaccine protective against measles only is also available and called Attenuvax®. All three of these vaccines are produced by Merck and Co, Whitehouse Station, NJ.

    Measles vaccines are live, attenuated (weakened) virus vaccines. This means that after injection, the virus grows, and causes a harmless infection in the person immunized. The body’s immune system fights the infection caused by the weakened virus, which results in the person becoming immune to measles infection.

  2. Who should get this vaccine?
    Two doses of measles vaccine (given as combination MMR) are recommended for all children and adolescents and certain adults.

  3. Why do health care workers need proof of immunity to measles?
    People who work in medical facilities are at much higher risk for acquiring and transmitting measles than the general population is. Making sure that all health care workers are immune to this disease protects both the employee and the patients with whom he or she may have contact. All people working in a health care facility should have evidence of immunity to measles, including full- or part-time employees, medical or non-medical, paid or volunteer, students, and those with or without direct patient responsibilities. Health care workers should have one of the following: two doses of MMR vaccine, a laboratory test that indicates immunity, or written evidence of previous measles disease diagnosed by a physician.

  4. How safe is this vaccine?
    Hundreds of millions of doses of measles vaccine have been given in the United States, and its safety record is excellent. Because it is a live vaccine, side effects following vaccination can be similar to a very mild case of measles. More than 80% of children will have no side effects at all.

  5. What side effects have been reported with this vaccine?

    Fever is the most common side effect, occurring in 5%-15% of vaccine recipients. About 5% of people develop a mild rash. When they occur, fever and rash appear 7-10 days after vaccination. About 25% of adult women receiving MMR vaccine develop temporary joint pain, although this symptom is related to the rubella component of the combined vaccine. Joint pain only occurs in women who are susceptible to rubella at the time of vaccination.

    More severe reactions, including allergic reactions, are rare. About one person per million develops inflammation of the brain due to the measles component of the MMR vaccine.

  6. If someone develops a rash after getting the MMR vaccine, is he or she contagious?
    Transmission of the measles vaccine virus does not occur from a vaccinated person, including those who develop a rash. No special precautions (e.g., staying home from school or work) need to be taken.

  7. Does the MMR vaccine cause autism?

    Current scientific evidence does not support the hypothesis that measles-mumps-rubella (MMR) vaccine causes autism. The question about a possible link between MMR vaccine and autism has been extensively reviewed by independent groups of experts in the U.S. including the National Academy of Sciences' Institute of Medicine. These reviews have concluded that the available epidemiologic evidence does not support a causal link between MMR vaccine and autism.

    The MMR-autism theory had its origins in research by Andrew Wakefield and colleagues in England. Those colleagues have retracted their article about the theory. Studies that suggest a cause-and-effect relationship between MMR vaccine and autism have received a lot of attention by the media. However, these studies have significant weaknesses and are far outweighed by many population studies that have consistently failed to show a causal relationship between MMR vaccine and autism. For a summary of the issues surrounding this topic, please read "Vaccines and Autism," by Paul A. Offit, MD, Director, Vaccine Education Center, Children's Hospital of Philadelphia. This article can be accessed online at: For more information and links to related journal articles, visit IAC's "Autism" page at:

  8. How effective is this vaccine?
    The first dose of MMR vaccine produces immunity to measles in 95% to 98% of children vaccinated. The reason for the second dose is to protect those people who did not become immune after one dose. After two doses of measles vaccine, 99% of people become immune to the disease.

  9. Can the vaccine cause measles?
    As mentioned above, because the measles vaccine is "live," it can cause mild measles-like symptoms in some recipients, but it does not cause measles.