To determine the age-specific seropositivity and the level of measles specific IgG in vaccinated adolescents, the measles specific IgG titers were measured from the sera of junior & senior high school students in Seoul, Korea.

From May to July in 1996, 216 sera were collected from junior & senior high school students(male : 110, female : 106) aged 12 to 17 years who were vaccinated and had no history of natural measles. Measles specific IgG titers were measured using ELISA method(SIATM Measles IgG Kit, Sigma Co. St. Louis, Mo).

The seropositivity of measles specific IgG in vaccinated adolescents aged 12 to 17 years was 91.2%. There were no significant correlations between age and seropositivity as well as between age and measles specific IgG level.

We consider that our data suggest the necessity of revaccination of measles in adolescents. Further considerations should be required to establish an appropriate revaccination method and to evaluate the efficacy of revaccination of previously vaccinated adolescents.