what type of thing come after it ## Side Effects from MMR Immunization MEASLES. About 1 child in 5 will get a mild rash or fever beginning a week or two after vaccination. These reactions last for a few days. MUMPS. Very few children suffer any ill effects from mumps vaccine. Occasionally a child will get a mild fever one or two weeks after vaccination, or swollen glands in the cheeks or under the jaw. More serious reactions are extremely rare. RUBELLA. About 1 child out of 7 will get a rash or swelling in the lymph glands after getting rubella vaccine. This usually happens within a week or two after the shot and lasts 1 or 2 days. Also, about 1 child out of 100 will have some pain or stiffness in the joints, which can last from a few days to a few weeks. There is a small chance (less t...