Parents’ Guide to Childhood Immunization

Mumps
Mumps is best known for the swelling of the cheeks and jaw
that it causes, a result of inflammation of the salivary glands.
Mumps also causes a fever and headache. It is usually a mild
disease, but it leads to meningitis in about 1 child in 10 who get
the disease. It can occasionally cause encephalitis, deafness
(about 1 in 20,000 cases), or even death (about 1 in
10,000 cases).

MMR Vaccine Side Effects
Some children (about 1 in 5) get a mild rash or fever after MMR
vaccine. These reactions begin a week or two after the vaccination
and usually last for 1–3 days. About 1 child in 7 may get swollen
lymph glands, and 1 child in 100 may have pain or stiffness in the
joints that can last from a few days to a few weeks. There is a smaller
risk of painful swelling of the joints (arthritis). These joint
symptoms occur more often in adults, especially women.
Febrile seizures (seizures caused by a fever) have occasionally
been reported after MMR vaccination. These usually happen 1 or 2
weeks after the shot and are caused by the fever than can accompany
the vaccination rather than by the vaccine itself. Children
recover from febrile seizures quickly and they do not cause
permanent harm.
There have been reports of children getting encephalitis
(inflammation of the brain) after an MMR shot. This happens so
rarely — less than once in a million shots — that experts can’t be
sure whether the vaccine is the cause or not. Remember, though,
that if the same million children were infected with measles, about
1,000 of them would get encephalitis.

MMR Vaccine Precautions
In addition to the normal precautions for all vaccines, shown on
page 30, children who are known to have a severe allergy to gelatin
or the antibiotic neomycin should not get MMR. A child who has a
suppressed immune system, either because of a disease such as
cancer or HIV infection or a medication such as steroids, should be
evaluated by a doctor before getting MMR. A child who has recently
gotten a transfusion or other blood product might have to wait up
to several months before getting MMR.
Two live vaccines (for example, MMR and varicella) may be
given on the same day or separated by at least 4 weeks. But they
should not be given less than 4 weeks apart, because they might
interfere with each other. MMR and inactivated (killed) vaccines
may be given together, or at any time in relation to each other.
Children who have gotten MMR vaccine cannot infect people they
come in contact with.

Combination Vaccines
Several vaccines are sometimes combined into a single shot. These are called combination vaccines. Some combination vaccines are used routinely - DTaP is a combination; so is MMR. There are currently four other combination vaccines available for children. One combines DTaP and Hib vaccines; the second Hib and hepatitis B; the third combines DTaP, hepatitis B, and polio, and the fourth combines measles, mumps, rubella and varicella. The advantage of combination vaccines is, of course, that your children get the protection of all the component vaccines while getting fewer injections.  Each of these vaccines has certain restrictions, and not all providers carry them. But ask your provider about them if you are interested in reducing the number of shots your child needs. 

http://www.cdc.gov/vaccines/vpd-vac/mumps/downloads/pg_why_vacc_mumps.rtf