Measles antibody in the children in Ubon Ratchathani province.

Measles is a highly contagious disease, preventable by vaccine. Measles epidemics have been dramatically controlled since the introduction of live attenuated measles vaccine. Measles antibody is used as an indicator of previous natural infection or vaccination, and also as a marker of protective immunity. The authors determined measles IgG levels in 1,176 children in Ubon Ratchathani province by ELISA from September 1998 to January 1999. Two- hundred and sixty- five cases (22.5%) had antibodies below the protective level (< 320 mIU/ml). Antibodies were high during the neonatal period, then declined to below the protective level at 4-6 months of age, and were negative at age 7-11 months. An increase in antibody level after 1 year old might be the result of measles immunization at 9-12 months of age, then antibodies decreased to the lowest level at 3-5 years after immunization or 4-6 years of age. A second dose of immunization will increase the number of children who have antibodies above the protective level better than one dose of immunization and it is recommended to revaccinate at 4-6 years of age. There was no statistical difference of measles antibody between boys and girls in all age groups.