Age Related Measles Antibody Levels After Vaccination

Yoo, Jin Woo; Sohn, Hyang Eun; Chung, Nak Eun; Choi, Tae Yeal

Abstract

BACKGROUND
A two-dose measles vaccination schedule is recommended routinely for either school entry or 11 to 13 years of age in America since 1989. But, several studies were performed on measles antibody in Korea and it remains controversial whether a second dose measles vaccine after 15 months is necessary. To generate baseline data, measles antibody prevalence and its levels according to different age groups in children and young adults in Taejon area were studied.
METHODS
A total of 261 subjects at 3 to 21 years of age, who had received a single dose of measles vaccine, were tested for measles antibody by quantitative alpha enzyme immunoassay. The subjects were divided into five age-groups based on the educational system (preschool, elementary school, middle school, high school, young-adult).
RESULTS
The seropositivity rates were 97.7% and not significantly different among groups. The expected tendency of declining antibody levels with advancing age, as reported by other studies, was not observed in this study. Except for between Group I and Group II, no significant difference was noted in the antibody levels among the five age groups. Group II showed significantly higher antibody levels than those of Group I (P=0.0025).
CONCLUSIONS
No declining tendency of measles antibody levels with advancing age is different from many other studies and contradicts the current recommendations for supplementary vaccinations after 15 months. These might reflect the regional characteristics of the study population in Taejon area and current vaccination rate. Therefore, futher studies with larger population in different geographic regions by quantitative EIA would be needed.