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Vaccine Information

Entry last updated: 10/31/2005

- Understanding the Disease
- Available Vaccines
- History of the Vaccine
- Who Should and Should Not Receive the Vaccine
- Dose Schedule
- Effectiveness of the Vaccine
- Known Side Effects
- Related Issues
- Key References and Sources of Additional Information
- State Vaccine Requirements
- Important Facts for Parents to Know
- Frequently Asked Questions
- CDC Vaccine Information Statement

Understanding the Disease

Measles is a serious disease caused by a highly contagious virus, which spreads when people touch or breathe in infectious droplets passed by coughing and sneezing. Measles begins with fever followed by cough, runny nose, and conjunctivitis ("pink eye"). Infections of the middle ears, pneumonia, croup, and diarrhea are common complications. Measles encephalitis (an infection of the brain) occurs in 1 per 1,000 cases of natural measles, frequently resulting in permanent brain damage in the survivors. Approximately 5% of children (500 out of 10,000) with measles will develop pneumonia. In addition, 1 to 3 of every 1,000 children who get measles in the United States dies from the disease.

Death is more common in infants, in malnourished children, and among immunocompromised persons, including those with leukemia and HIV infection.

Subacute sclerosing panencephalitis (SSPE) is a rare fatal illness caused by ongoing measles virus infection of the brain. Symptoms of brain damage usually begin 7 to 10 years after infection. Death occurs 1-3 years after the onset of symptoms. Risk factors for developing SSPE include developing measles infection at a young age. The incidence of SSPE is estimated to be between 7-11 cases/100,000 cases of measles. Measles vaccine virus was not associated with SSPE.

Prior to licensure of the first measles vaccine in 1963, virtually every person in the U.S. got the measles by age 20. Since the vaccine became available, there has been a 99% reduction in the incidence of measles. However, measles is still being “imported” from other countries. The most recent outbreaks occurred in the U.S. between 1989 and 1991, resulting in 755,000 cases and 123 reported deaths.

Available Vaccines

The measles vaccine is available as:

  • MMR (Measles-Mumps-Rubella)
  • Monovalent Measles (alone)

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

Product: Attenuvax® (Monovalent Measles)
Manufacturer: Merck
Year licensed: 1963

All MMR vaccines are available containing no thimerosal. For information on the thimerosal content of vaccines, see the Food and Drug Administration at

History of the Vaccine

The first measles vaccine was licensed for use in the U.S. in 1963. Today, measles vaccine is generally given in combination with mumps and rubella vaccines (MMR).

Originally, just one dose of MMR vaccine was recommended, and about 95% of children were protected. 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 so that almost all children (99.7%) would be protected. This change and a higher vaccination rate have nearly eliminated these three diseases in the United States.

Who Should and Should Not Receive this Vaccine

Who should receive the MMR vaccine?

  • All infants 12 months of age or older
  • Susceptible adults who do not have documented evidence of measles immunity, such as a physician-diagnosed case of measles, a blood test showing the presence of measles antibody, or proof of receiving measles vaccine.

Immunity against measles is particularly important for adults at high risk for measles exposure, including college students and health care workers. People born before 1957 who are not in one of these high-risk categories are generally considered immune to measles through environmental exposure.

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
- Children whose mothers or other household members are pregnant, as immunizing these contacts poses no risk to the pregnant individual

Administering the vaccine within 72 hours to people who have been exposed to measles may prevent them from developing the disease.

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.

Who should receive the monovalent measles vaccine?

  • Infants 6 to 12 months of age if there is a measles outbreak, though MMR may be used if this vaccine is unavailable
  • Infants 6 to 11 months of age traveling to areas where measles is prevalent, though MMR may be used if this vaccine is unavailable
  • People who cannot receive one or both of the other vaccines included in MMR
  • People who have proof of immunity to one or both of the other diseases that MMR prevents, though MMR is usually recommended

Who should not receive the monovalent measles vaccine?

  • People with serious allergies to gelatin or any of the other components of the vaccine
  • Women should not become pregnant within one month of receiving the monovalent measles vaccine.
  • 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 monovalent measles 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

The complete childhood immunization schedule can be found at:

The summary of adolescent/adult immunization recommendations can be found at:

Dose Schedule

The measles vaccine is usually given with the mumps and rubella vaccines in people 12-15 months of age and older.

Two doses of MMR vaccine administered on or after the first birthday are recommended for all children, including those who previously received the monovalent measles vaccine. 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.

Students who are exposed to an outbreak who have not already received two doses of the vaccine, and who do not have other proof of immunity, may be excluded from school for the entire duration of the outbreak or required to receive the measles vaccination. The second dose of the measles vaccine series is effective when given as early as one month after the first dose and this schedule is used when protection is needed quickly.

Effectiveness of the Vaccine

Ninety-five percent of those who receive the MMR or monovalent measles vaccine at 12 months of age or older are immune after the first dose. After the second dose, 99.7% of those immunized are protected. 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 they receive the vaccine.

About 15% of women who receive 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.

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; therefore, the same reactions may occur after immunization with monovalent measles vaccine.

Related Issues

There are hypotheses that the MMR vaccine causes autism. However, the best available science indicates that the development of autism is unrelated to use of the MMR or any other vaccine. One small study seemed to postulate such a link but has subsequently been disproved by many other, larger studies. Ten of the thirteen authors of that study later retracted from their suggestion of a link between MMR vaccine and autism.

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 and is easily treated. ITP is generally much less serious than measles, mumps, or rubella. A recent study found that children who had ITP and later received the MMR vaccine had no vaccine-associated recurrences.

The following provide additional information on the safety of the MMR vaccine:

  • Centers for Disease Control and Prevention, National Immunization Program. (2001). Vaccines and autism theory [Web page]. Available online:
  • Halsey NA and Hyman SL. (2001). Measles-mumps-rubella vaccine and autistic spectrum disorder: Report from the New Challenges in Childhood Immunizations Conference. Pediatrics, 107(5), e84.
  • Institute of Medicine. (2001). Immunization safety review: Measles-Mumps-Rubella vaccine and autism. Washington, DC: National Academy Press. Available online:
  • Miller E, Waight P, Farrington CP, Andrews N, Stowe J, and Taylor B. (2001). Idiopathic thrombocytopenic purpura and MMR vaccine. Archives of Disease in Childhood, 84(3), 227-229
  • Prober CG. (1999). Evidence shows genetics, not MMR, determines autism. AAP News, 15(12), 24. Available online:
  • Rodier PM. (2000). The early origins of autism. Scientific American, 282(2), 56-63.
  • Stratton K, Gable A, Shetty P, and McCormick M (Eds.). (2001). Immunization safety review: Measles-mumps-rubella vaccine and autism. Washington DC: National Academy Press. Available online:
  • Taylor B, Miller E, Farrington CP, Petropoulos MC, Favot-Mayaud I, Li J, and Waight PA. (1999). Autism and measles, mumps, and rubella vaccination: No epidemiological evidence for causal association. Lancet, 353(9169), 2026-2029.
  • Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Harvey P, Valentine A, Davies SE, and Walker-Smith JA. (1998). Ileal-lymphoid-modular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet, 351(9103), 637-641.

Key References and Sources of Additional Information

  • American Academy of Pediatrics (AAP), Committee on Children with Disabilities. (2001). The pediatrician’s role in the diagnosis and management of autistic spectrum disorder in children. Pediatrics, 107(5), 1221-1226.
  • AAP, Committee on Infectious Diseases. (2000). Measles. In LK Pickering (Ed.), Red Book: Report of the Committee on Infectious Diseases (25th ed., pp. 385-396). Elk Grove Village, IL: Author.
  • AAP, Committee on Infectious Diseases and Committee on Pediatric AIDS. (1999). Measles immunization in HIV-infected children. Pediatrics, 103(5 Pt 1), 1057-1060.
  • 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(9), 656-661.
  • Centers for Disease Control and Prevention (CDC). Advances in global measles control and elimination: Summary of the 1997 international meeting. Morbidity and Mortality Weekly Report, 47(RR-11), 1-23. Available online:
  • 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. Available online:
  • CDC, National Immunization Program (NIP). (1998). Measles, mumps, and rubella vaccines: What you need to know [Vaccine Information Statement (VIS)]. Available online:
  • CDC, NIP. (2000). Measles. In Epidemiology and prevention of vaccine-preventable diseases (“The Pink Book”) (6th ed., pp. 117-142). Atlanta: Author. Available on-line:
  • CDC, NIP. (2001). Measles. In Vaccine-preventable childhood diseases [Online fact sheet]. Available online:
  • Duclos P and Ward BJ. (1998). Measles vaccines: A review of adverse events. Drug Safety, 19(6), 435-454.
  • Humiston SG and Good C. (2000). Vaccinating your child: Questions and answers for the concerned parent. Atlanta: Peachtree Publishers.
  • MMR The facts.
  • Offit PA and Bell LM. (1999). Vaccines: What every parent should know (Rev. ed.). New York: IDG Books.
  • Patja A, Davidkin I, Kurki T, Kallio MJ, Valle M, and Peltola H. (2000). Serious adverse events after measles-mumps-rubella vaccination during a fourteen-year prospective follow-up. Pediatric Infectious Disease Journal, 19(12), 1127-1134.
  • Salmon DA, Haber M, and Chen RT. (1999). Health consequences of religious and philosophical exemptions from immunization laws: Individual and societal risks of measles. Journal of the American Medical Association, 282(1), 47-53. Available online:
  • Siegel M, Fuerst HT, and Peress NS. (1966). Comparative fetal mortality in maternal viral diseases: A prospective study on rubella, measles, mumps and chickenpox and hepatitis. New England Journal of Medicine,(274), 768-771.

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Including available vaccines, history of the vaccine, who should and should not receive it, dose schedules, effectiveness, known side effects, and related issues.

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Important Facts for Parents to Know about the Measles Vaccine

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Frequently Asked Questions about the Measles Vaccine

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CDC Vaccine Information Statement for Measles

Information provided by the Centers for Disease Control and Prevention on specific vaccines and the diseases they can prevent. Healthcare providers are required to give these to their patients before administering a vaccine.

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