Measles, Mumps, Rubella (MMR)

Updated: April 22, 2010

Table of Contents

    Understanding the Disease

    Rubella is caused by a virus that is transmitted from person to person in mucus droplets coughed or sneezed into the environment. Rubella usually is a mild illness. Symptoms include low-grade fever and swollen lymph nodes in the back of the neck followed by a generalized rash. Complications may include joint pain, a temporary decrease in platelets, and encephalitis (inflammation of the brain). Temporary arthritis may also occur, particularly in adolescents and adult women.

    Rubella in expectant women often leads to congenital rubella syndrome (CRS) in their fetuses. This is a devastating disease characterized by deafness, mental retardation, cataracts and other eye defects, heart defects, and diseases of the liver and spleen that may result in a low platelet count with bleeding under the skin. The incidence and severity of congenital defects are greater if infection occurs during the first month of gestation. Up to 85% of expectant mothers infected in the first trimester will have a miscarriage or a baby with CRS.

    The World Health Organization estimated that, in 1999, 110,000 infants were born with CRS worldwide. Although most CRS occurs in developing countries, it also continues to occur in the U.S., mostly among unimmunized Hispanics.

    Before a vaccine was available, there was a rubella outbreak in the U.S. (1963 to 1964), during which 12 million people developed the disease. Because many of those infected were expectant mothers, 11,000 fetuses died and 20,000 babies were born with permanent disabilities as a result of exposure to the virus. The number of cases of rubella fell very sharply once the rubella vaccine was licensed in 1969; today there are fewer than 1,000 cases of rubella reported each year in the U.S. on average and less than 10 cases of congenital rubella syndrome.

    Because of intense misinformation about MMR in the United Kingdom, MMR vaccine coverage has declined across Europe, resulting in outbreaks of measles and mumps in multiple countries, including the United States and Canada, and congenital rubella in the Netherlands and Canada. There were 42 cases of rubella among pregnant women with two fetal deaths and 12 affected infants. Ironically, one of the few known causes of autism was the congenital rubella syndrome, autism having occurred in 20% of rubella-affected babies prior to the licensure of rubella vaccine. MMR vaccine, therefore, protects against autism by preventing congenital rubella syndrome.

    Available Vaccines

    The rubella vaccine is available as:

    • MMR (Measles-Mumps-Rubella)
    • MMRV (Measles-Mumps-Rubella-Varicella Virus Vaccine Live)
    • Rubella (alone)

    Product: ProQuad® (MMRV)
    Manufacturer: Merck
    Year licensed: 2005

    Product: M-M-R® II
    Manufacturer: Merck
    Year licensed: 1971

    Neither MMR or MMRV vaccines contain thimerosal.

    History of the Vaccine

    The first vaccines for rubella were licensed in 1969. Today rubella vaccine is given in combination with measles and mumps vaccines (MMR) or MMR combined with varicella (MMRV).

    Originally, just one dose of the MMR vaccine was recommended. In 1989, the American Academy of Family Physicians, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, changed the recommendation to two doses. This change and a higher vaccination rate have nearly eliminated these three diseases in the United States. Continued immunization of children is needed to prevent the spread of these infections imported from other countries.

    Who Should and Should Not Receive the Vaccine

    Who should receive the MMR vaccine?

    • All infants 12 months of age or older
    • Susceptible adults

    Because of the risk of CRS, it is particularly important that post-pubertal women be immune to rubella. Routine screening of pregnant women for rubella immunity is recommended and susceptible individuals should be vaccinated when it is known that they are not pregnant. Vaccination in case of susceptible pregnant women is often given immediately after giving birth.

    People susceptible to rubella working in educational institutions and childcare centers should be immunized to prevent transmission of rubella virus to pregnant women, as well as for their own protection.

    Frequently, it is believed that members of the following groups should not receive the vaccine. In fact, susceptible members may still receive the vaccine:
    - Women who are breast feeding
    - Individuals who have HIV infection but no symptoms of AIDS
    - Susceptible children whose mothers or other household members are pregnant, as immunizing these contacts presents no risk to the pregnant individual

    Who should not receive the MMR vaccine?

    • People with serious allergies to gelatin or any of the other components of the vaccine
    • Women who are pregnant or trying to conceive. Moreover, women should not become pregnant within 28 days after immunization with MMR.
    • Immunocompromised persons (with the exception of HIV-infected persons who have no symptoms of AIDS, as noted above) and persons receiving cancer chemotherapy or high doses of steroids
    • People receiving blood products (except washed red blood cells) such as immune globulin should have the MMR vaccine deferred for 3 to 11 months depending on the blood product and dosage administered.
    • People who are moderately or severely ill should consult with their physician before receiving any vaccine.

    This vaccine is recommended by:

    • Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention
    • American Academy of Pediatrics
    • American Academy of Family Physicians

    Summaries of the childhood, adolescent, and adult immunization recommendations can be found at the CDC site.

    Dose Schedule

    Two doses of MMR vaccine administered on or after the first birthday are recommended for all children. The first dose is generally given at 12 to 15 months of age, and the second dose is generally given at four to six years of age. There must be a minimum of four weeks between doses. The second dose of MMR provides an added safeguard against all three diseases, but is recommended primarily to prevent outbreaks of measles.

    Effectiveness of the Vaccine

    Ninety-five percent of those who receive the MMR or rubella vaccine at one year of age or older are immune after the first dose. Immunity is lifelong.

    Known Side Effects

    Nearly all children who get the MMR vaccine (more than 80%) will have no side effects. Most children who have a side effect will have only a mild reaction, such as soreness, redness or swelling where the shot was given, mild rash, mild to moderate fever, swelling of the lymph glands, and temporary pain, stiffness, or temporary swelling in the joints.

    In about 5% to 15% of children given MMR, a fever in excess of 103 degrees F may occur—usually beginning about 7 to 12 days after the vaccine has been administered.

    About 15% of women who receive the rubella vaccine or MMR will develop acute arthritis or swelling of the joints. This condition is usually very short-lived.

    In rare cases (about 3 children out of 10,000 given MMR, or 0.03% of recipients) a moderate reaction such as seizure related to high fever may occur. The risk of a febrile seizure after the first dose of MMRV is increased by an additional child per 1000 (compared to children who got MMR and varicella vaccine at different sites on the same day).

    In very rare cases (far less than 1 child out of 10,000 given MMR), children have a serious reaction, such as lowered consciousness, coma, or hypersensitivity (anaphylaxis)—swelling inside the mouth, difficulty breathing, low blood pressure, and rarely, shock. Even more rarely, children may have low blood platelets that can lead to a temporary bleeding problem that is described in more detail in the “Related Issues” section below. Since 1990, there have been 11 case reports of anaphylaxis in those who received the vaccine. Thirty to 40 million children were vaccinated during this time period. No children who experienced such a reaction died as a result.

    In extremely rare cases (less than 1 child out of 1,000,000 given measles vaccine) children have developed encephalitis 6-15 days after vaccination.

    MMR side effects are largely due to the measles vaccine that it contains. Adverse reactions to the rubella vaccine may include arthritis or joint swelling as described above.

    Reimmunization with MMR vaccine is not associated with an increased incidence of reactions even when a person is already immune to one or more of the viruses.

    Related Issues

    Persons exposed to infants with congenital rubella syndrome, particularly post-pubertal women for whom rubella immunity is critical, should be aware that these infants may shed rubella virus for at least one year.

    Researchers estimate that about one in every 22,000 MMR vaccinations could result in a child developing a temporary bleeding disorder called idiopathic thrombocytopenic purpura (ITP). ITP is rarely dangerous — generally much less serious than measles, mumps, or rubella — and is easily treated. A recent study found that children who had ITP and later received the MMR vaccine had no vaccine-associated recurrences. ITP can also occur as a result of rubella infection.

    MMR vaccine is not given to pregnant women or within 4 weeks of conception because of the concern that the rubella vaccine virus could theoretically harm the fetus. In fact, among 293 infants delivered to women who were inadvertently immunized within 2 weeks prior to conception or up to 6 weeks after conception, none had evidence of congenital rubella syndrome.

    Key References and Sources of Additional Information

    • American Academy of Pediatrics (AAP), Committee on Infectious Diseases. (2009). Rubella. In LK Pickering (Ed.), Red Book: Report of the Committee on Infectious Diseases (28th ed., pp. 579-584). Elk Grove Village, IL.  
    • Barlow WE, Davis RL, and Glasser JW. (2001). The risk of seizures after receipt of whole-cell pertussis or measles, mumps, and rubella vaccine. New England Journal of Medicine, (345), 656-61. 
    • Centers for Disease Control and Prevention (CDC). (1998). Measles, mumps, and rubella: Vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome, and control of mumps: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report, 47(RR-8), 1-57.  
    • CDC. (2001). Revised ACIP recommendation for avoiding pregnancy after receiving a rubella-containing vaccine. MMWR 50(49): 1117. 
    • Hahné S, Macey J, van Binnendijk R, et al. 2009. Rubella outbreak in the Netherlands, 2004-2005. High burden of congenital infection and spread to Canada. Ped Infect Dis J 28(9); 795800. 
    • Pineda D and Myers MG. 2007. Human fetal links with some vaccines.
    • Myers MG, Pineda D. 2008. Do vaccines cause that?! A guide for evaluating vaccine safety concerns. I4PH Press, Galveston.

    CDC Information