Ki Wook Yun1, Hoan Jong Lee2, Ji Young Park3, Hye-Kyung Cho4, Yae-Jean Kim5, Kyung-Hyo Kim6, Nam Hee Kim7, Young Jin Hong8, Dong Ho Kim9, Hwang Min Kim10, Sung-Ho Cha11. 1. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: pedwilly@snu.ac.kr. 2. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: hoanlee@snu.ac.kr. 3. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: jiyoung320.park@samsung.com. 4. Department of Pediatrics, Gachon University College of Medicine, Incheon, Republic of Korea. Electronic address: hkcho@gilhospital.com. 5. Departments of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: yaejeankim@skku.edu. 6. Department of Pediatrics, School of Medicine, Ewha Womans University, Seoul, Republic of Korea. Electronic address: kaykim@ewha.ac.kr. 7. Department of Pediatrics, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Republic of Korea. Electronic address: peddream@medimail.co.kr. 8. Department of Pediatrics, Inha University College of Medicine, Incheon, Republic of Korea. Electronic address: hongyjin@inha.ac.kr. 9. Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Republic of Korea. Electronic address: kdh@kcch.re.kr. 10. Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea. Electronic address: khm9120@yonsei.ac.kr. 11. Department of Pediatrics, College of Medicine, Kyunghee University, Seoul, Republic of Korea. Electronic address: sunghocha@khu.ac.kr.
Abstract
BACKGROUND: This study was performed with the aim of determining the long-term immunogenicity of an inactivated, Vero cell culture-derived Japanese encephalitis (JE) vaccine (JE-VC) and an inactivated, mouse brain-derived JE vaccine (JE-MB) after the 1st booster dose at 2 years of age, as well as the safety and immunogenicity of the 2nd booster dose of JE-VC at 6 years of age, in children primed and given a 1st booster dose of either JE-VC or JE-MB. METHOD: In this multicenter, open-label clinical trial, the study population consisted of healthy Korean children (aged 6 years) who participated in the previous JE vaccine trial. All subjects were subcutaneously vaccinated once for the booster immunization with Boryung Cell Culture Japanese Encephalitis Vaccine® (JE-VC). RESULT: Approximately 4 years after the 1st booster dose of JE-VC, the seroprotection rate (SPR) and geometric mean titer (GMT) of the neutralizing antibody were 100% and 1113.8, respectively. In children primed and given a 1st booster dose of JE-MB, the SPR and GMT were 88.5% and 56.3, respectively. After the 2nd booster dose of JE-VC, all participants primed and given a 1st booster dose of either JE-MB or JE-VC were seroprotective against JE virus. The GMT of the neutralizing antibody was higher in children primed and given a 1st booster dose of JE-VC (8144.1) than in those primed and given a 1st booster dose of JE-MB (942.5) after the vaccination (p < 0.001). In addition, the 2nd booster dose of JE-VC showed a good safety profile with no serious vaccine-related adverse events. CONCLUSION: The 1st booster dose of JE-VC and JE-MB showed long-term immunogenicity of at least 4 years, and the 2nd booster dose of JE-VC showed a good safety and immunogenicity profile in children primed and given a 1st booster dose of either JE-VC or JE-MB. ClinicalTtrials.gov Identifier: NCT02532569.
BACKGROUND: This study was performed with the aim of determining the long-term immunogenicity of an inactivated, Vero cell culture-derived Japanese encephalitis (JE) vaccine (JE-VC) and an inactivated, mouse brain-derived JE vaccine (JE-MB) after the 1st booster dose at 2 years of age, as well as the safety and immunogenicity of the 2nd booster dose of JE-VC at 6 years of age, in children primed and given a 1st booster dose of either JE-VC or JE-MB. METHOD: In this multicenter, open-label clinical trial, the study population consisted of healthy Korean children (aged 6 years) who participated in the previous JE vaccine trial. All subjects were subcutaneously vaccinated once for the booster immunization with Boryung Cell Culture Japanese Encephalitis Vaccine® (JE-VC). RESULT: Approximately 4 years after the 1st booster dose of JE-VC, the seroprotection rate (SPR) and geometric mean titer (GMT) of the neutralizing antibody were 100% and 1113.8, respectively. In children primed and given a 1st booster dose of JE-MB, the SPR and GMT were 88.5% and 56.3, respectively. After the 2nd booster dose of JE-VC, all participants primed and given a 1st booster dose of either JE-MB or JE-VC were seroprotective against JE virus. The GMT of the neutralizing antibody was higher in children primed and given a 1st booster dose of JE-VC (8144.1) than in those primed and given a 1st booster dose of JE-MB (942.5) after the vaccination (p < 0.001). In addition, the 2nd booster dose of JE-VC showed a good safety profile with no serious vaccine-related adverse events. CONCLUSION: The 1st booster dose of JE-VC and JE-MB showed long-term immunogenicity of at least 4 years, and the 2nd booster dose of JE-VC showed a good safety and immunogenicity profile in children primed and given a 1st booster dose of either JE-VC or JE-MB. ClinicalTtrials.gov Identifier: NCT02532569.