Mumps and mumps vaccine: A global review

Mumps is an acute infectious disease caused by a paramyxovirus. Although th e disease is usually mild, up to 10% of patients can develop aseptic mening itis; a less common but more serious complication is encephalitis, which ca n result in death or disability. Permanent deafness, orchitis, and pancreat itis are other untoward effects of mumps. Based on data reported to WHO up to April 1998, mumps vaccine is routinely used by national immunization pro grammes in 82 countries/areas: 23 (92%) of 25 developed countries, 19 (86%) of 22 countries with economies in transition (mainly the Newly Independent States of the former Soviet Union), and 40 (24%) of 168 developing countri es. Countries that have achieved high coverage have shown a rapid decline i n mumps morbidity. Furthermore, in many of these countries, mumps-associate d encephalitis and deafness have nearly vanished. This review considers the disease burden due to mumps; summarizes studies on the immunogenicity, eff icacy, and safety of different strains of mumps vaccine; and highlights les sons learned about implementing mumps immunization in different countries. Countries already using mumps vaccine should monitor immunization coverage and establish routine mumps surveillance with investigation of outbreaks. W here mumps is targeted for elimination, countries need to add a second dose of mumps vaccine for children, keeping in mind that the disease may still occur in susceptible adults.