title: Seropositivity of Varicella zoster virus in vaccinated Korean children and MAV vaccine group.
abstract: In 2005, a single-dose varicella vaccination was incorporated into the national immunization program in Korea. Although the Oka strain is the most commonly circulating Varicella zoster virus (VZV) genotype in Korea, a domestically manufactured vaccine based on the MAV strain is widely distributed in Korea. High vaccination coverage was achieved, but breakthrough infections were frequently reported. Therefore, in this study, we aimed to analyze the maintenance of immunity after single-dose vaccination and to compare the immunity provided by the MAV and Oka vaccines. Enzyme-linked immunosorbent assays of samples from 715 vaccinated Korean children were used to assess seropositivity rates against VZV. Additionally, fluorescent-antibody-to-membrane-antigen (FAMA) tests were performed in 35 individuals in the MAV vaccine group, and seropositivity rates against the Oka strain were determined. The progressive decrease of the seropositivity rate was demonstrated from ages 1 to 4 as follows: 65% in age 1, 59% in age 2, 53% in age 3, 49% in age 4. It then increased to 62% in age 5 and 70% in age 6. Both the MAV and Oka vaccine groups showed a progressive decrease of the seropositivity rate from the age of 1 to 4 years, but the MAV vaccine group had higher seropositivity rates. In FAMA test, the MAV group demonstrated 71% seropositivity against the Oka strain. This study indicates that immunity wanes after single-dose varicella vaccination and that the MAV vaccine is not inferior to the Oka vaccine in providing immunity against VZV. The MAV vaccine also induced cross-immunity against circulating Oka strain.
authors.affiliation: a Pediatrics, College of Medicine, The Catholic University of Korea , Dongdaemungu, Seoul , Republic of Korea.
authors.forename: Ui Yoon
authors.initials: UY
authors.lastname: Choi
authors.affiliation: b The Vaccine Bio Research Institute, College of Medicine, The Catholic University of Korea , Seoul , Republic of Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Huh
authors.affiliation: c The Catholic University of Korea, St. Vincent's Hospital , Gyeonggi-do, Gyeonggi-do , Republic of Korea.
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: d Department of Pediatrics , College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea , Seoul , Republic of Korea.
authors.forename: Jin Han
authors.initials: JH
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D019433:Chickenpox Vaccine / Q000008:administration & dosage* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D056910:Republic of Korea
chemical_list: D000914:Antibodies, Viral; D019433:Chickenpox Vaccine
keywords: MAV vaccine; Varicella zoster virus; Varicella zoster virus vaccine; children; seropositivity