The mumps vaccine is usually given in combination with measles and rubella vaccine (MMR). The attenuated strains of mumps virus that are currently used for the production of live mumps vaccines are all considered to be safe and efficacious. In order to avoid possible interference with persistent maternal antibodies, the first of the two recommended doses of the vaccine is usually given at 12–18 months of age. A single dose of mumps vaccine, either as single antigen or in combination, has a protective efficacy of 90–96%.The second dose provides protection to most individuals who did not respond to the first and should be given after a minimum interval of 1 month. In some countries the second dose is given at the age of 4–6 years.