R.,
I just had to get my booster updated for myself, as the measles titer was below normal levels & I will be in contact with patients shortly through school.
The vaccine is given subcutaneously (ie. liquid is injected under the surface of the skin, not into the muscle), which can lead to some swelling, itching or a rash.
From the CDC website here are the possible side effects, and their likelihood of occurrence:
What are the risks from MMR vaccine?
A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions.
The risk of MMR vaccine causing serious harm, or death, is extremely small.
Getting MMR vaccine is much safer than getting measles, mumps or rubella.
Most people who get MMR vaccine do not have any serious problems with it.
Mild problems
Fever (up to 1 person out of 6)
Mild rash (about 1 person out of 20)
Swelling of glands in the cheeks or neck (about 1 person out of 75)
If these problems occur, it is usually within 6-14 days after the shot. They occur less often after the second dose.
Moderate problems
Seizure (jerking or staring) caused by fever (about 1 out of 3,000 doses)
Temporary pain and stiffness in the joints, mostly in teenage or adult women (up to 1 out of 4)
Temporary low platelet count, which can cause a bleeding disorder (about 1 out of 30,000 doses)
Severe problems (very rare)
Serious allergic reaction (less than 1 out of a million doses)
Several other severe problems have been reported after a child gets MMR vaccine, including:
Deafness
Long-term seizures, coma, or lowered consciousness
Permanent brain damage
These are so rare that it is hard to tell whether they are caused by the vaccine.
What if there is a serious reaction?
What should I look for?
Look for anything that concerns you, such as signs of a severe allergic reaction, very high fever, or behavior changes.
Signs of a severe allergic reaction can include hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, and weakness. These would start a few minutes to a few hours after the vaccination.
What should I do?
If you think it is a severe allergic reaction or other emergency that can’t wait, call 9-1-1 or get the person to the nearest hospital. Otherwise, call your doctor.
Afterward, the reaction should be reported to the Vaccine Adverse Event Reporting System (VAERS). Your doctor might file this report, or you can do it yourself through the VAERS websiteExternal Web Site Icon, or by calling 1-800-822-7967.
VAERS is only for reporting reactions. They do not give medical advice.
http://www.cdc.gov/vaccines/hcp/vis/vis-statements/mmr.html
If you or your child have gotten MMR vaccine, you should have been given a pamphlet from your doctor with this same information. T.