Immunizations - Measles, Mumps, and Rubella

Side Effects of Live Measles Mumps-Rubella (MMR) Vaccines

Common side effects from the MMR vaccination include fever, rash, and joint pain. Children are more likely to experience such side effects from the second dose (at 10 to 12 years) than from the first (at four to six years).

text continues below

Fever. About 5 - 15% of people who are vaccinated with any live measles virus vaccine develop a fever of 103 degrees or greater, usually between five and 15 days after the vaccination. It usually lasts one or two days but can persist up to five days. In very young children, seizures can occur from high fever eight to 14 days after vaccination, but they are rare and almost never have any long-term effects.

Swollen Glands. The live-mumps vaccine can cause mild swelling in the glands that are situated near the ears.

Joint Pain. Up to 25% of women have joint pain one to three weeks after a vaccination with a live-rubella virus; it lasts for one day to three weeks. Such pain does not usually interrupt daily activities. Rarely, it recurs or becomes persistent.

Allergic Reaction. People who have known anaphylactic allergies (very severe reactions) to eggs or neomycin are at high risk for a severe allergic response to the MMR vaccine. People with allergies that do not cause anaphylactic shock to these substances are not at higher risk for a serious allergic reaction to the vaccine. Mild allergic reactions may occur in some people, including rash and itching. A rash occurs in about 5% of people who are vaccinated with a live-measles vaccine. A live-mumps vaccination has caused rash and itching, but these symptoms are usually mild.

Interaction with Tuberculosis Test. The live-measles vaccine may interfere with a tuberculosis test, so the two should be administered at least four to six weeks apart. No evidence exists that the vaccine has an adverse effect on tuberculosis itself.

Mild Infection. One study suggests that a mild form of measles that has no symptoms may develop in previously immunized people who are exposed to the virus, although this mild infection may not be significant.

Idiopathic Thrombocytopenic Purpura (ITP). In about one in 22,300 doses, MMR can cause a rare bleeding disorder called idiopathic thrombocytopenic purpura (ITP). This can cause a purple bruise-like discolorations that can spread across the body, nose bleeds, or tiny red spots. It is nearly always mild and temporary. (Of note, the risk for ITP is much higher with the actual infections, particularly rubella.)

Note: Unsubstantiated Reports of Neurologic Side Effects and Decline in Immunization. Much controversy has arisen over unsubstantiated reports of neurologic side effects attributable to MMR. This is of great concern since such reports have resulted in a decline in immunizations in certain areas, notably affluent areas in England where the vaccination rate has dropped from 92% in 1996 to 84% currently. Here, measles outbreaks are now climbing and experts fear that unless immunization rates increase rapidly, case numbers will significant increase. In these and other regions, some parents mistakenly believe that the dangers of immunization outweigh a dangerous childhood illness that only older people remember. It should be strongly noted that measles still cause about 745,000 deaths in unvaccinated children who live in underdeveloped countries, mostly Africa.