(U of Maryland Med center)
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).
Fever. About 5% to 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
to 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.
Severe Side Effects. Much controversy has arisen over severe side effects of the MMR. This is of great concern
since the evidence of any serious problems is very weak and studies refuting them tend to be stronger. It should be
noted that in 2000, measles caused about a million deaths in children in countries where the vaccine is not used.
[Note: we at VacLib would consider this above paragraph to be nonsense. MMR has been proven to have links to
Autism. Children die of malnutrition, not measles.]
Researchers have confirmed that 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, nosebleeds, or tiny red spots. It is nearly
always mild and temporary. The risk for this is about one in 22,300 doses. (The risk is much higher with the actual infections,
There have been a few reports of encephalitis (inflammation in the brain) associated with the live-measles vaccine,
although the incidence of these events is no higher in immunized children than in nonimmunized children.
(Encephalitis is extremely rare in either case).