Prevalence and Persistence of Transferred Maternal Hepatitis. A Antibody During The Second Year of Life in Korean Infants

Cho, Hyung Joon; Lee, Mi Hee; Kim, Jong Hyun; Hur, Je Kyun; Lee, Jung Hyun; Kim, Jin Tack; Chung, Seung Yun; Kang, Jin Han

Abstract

BACKGROUND: Although the incidence of hepatitis A infection has dramatically declined in developed countries, it is still endemic in many of developing countries, and sporadic outbreak has developed in many middle classed endemic area. Many reports indicate that hepatitis A vaccine would have to be used for widespread immunization of infants, who live in endemic or non-endemic region, for eliminating this infection from circulation. Therefor, the optimal immunization schedule and dose of vaccine should be determined. Recent several studies suggested that high dose hepatitis A vaccination at the time of disappearance of maternal antibody promise protectable immunogenicity in infants. The purpose of our study to find out the prevalence and persistence of maternal HAV antibodies in Korean infants (below 2 years old age). METHODS: 60 mother without past-history of hepatitis A, and 300 heathy infants without history of hepatitis A vaccination and intra-familial contact history of hepatitis A were enrolled in this study. The infants below 2 years old age were classified into 5 groups as following; 0~3 months, 4~6 months, 7~9 months, 10~12 months, 13~24 months, and the number of each group were 60 and sex distribution of each group was equal. Positive rates of Anti-HAV were determined by ELISA. And comparisons of seroprevalence of anti- HAV between groups were analyzed by ANOVA repeated t-test. RESULTS: The seropositive rate of maternal group was 81.7%, and the seropositive rate of 0~3 months of age group was 43.3%. The seroprevalence of anti- HAV significantly declined after 4~6 months of age, and reached below 10% at the age of 7~9 months of age and the low rate of anti-HAV maintained until 2 years old age. And positive rates of anti-HAV showed no significant differences between males and females. CONCLUSION: The results of our study showed that the seroprevalence of anti-HAV significantly declined after 4~6 months of age and the anti-HAV almostly disappeared at 7~9 months of age. So, low seropositive rate of anti-HAV at 7 months of age may justify trials on infant vaccination in Korea.