A viral infection that causes swelling of the salivary glands, the glands that produce saliva in the mouth, for which there is a vaccine available.

Most children are immunized against mumps when they receive the MMR vaccine (measles, mumps, rubella) at about 15 months and between 11 and 12 years of age. {See immunization for recommended schedule.) The mumps virus is transmitted by airborne droplets, spread when an infected person (or an uninfected carrier) coughs or sneezes. The virus infects a person by passing through the respiratory system and settling in the salivary glands, most often the parotid gland located in front of the ear and just above the jawline. Most infected people—though not all—experience swelling on the side of one or both cheeks, and the area will be sensitive to the touch. Eating will cause pain, since it stimulates the salivary glands. Infected individuals may also have a...