Immunogenicity and Safety of I-HAV in Healthy Thai Children and Adolescents Lacking Protective Antibody After L-HAV

Summary

Hepatitis A virus (HAV) remains a common infection in Thai children. Two HAV vaccines are available: inactivated vaccine (I-HAV, 2 doses) and live-attenuated vaccine (L-HAV, single dose), but neither is included in Thailand's national immunization program. Our previous randomized, active-controlled, open-label, non-inferiority trial trial found that some participants remained seronegative after one L-HAV dose (anti-HAV IgG \<1 S/CO) (preliminary data). This study aims to evaluate the immunogenicity and safety of an additional dose of I-HAV in healthy Thai children and adolescents who did not develop protective antibody levels after a single dose of L-HAV.

Timeline

Start

2025-05-25

Primary completion

2025-06-22

Completion

2026-07-31

Publications

• Background Kunanitthaworn N, Mueangmo O, Saheng J, Wongjak W, Lertsiriladakul T, Chaito T, Nantarat P, Sudjaritruk T. Seroprevalence of hepatitis A virus antibodies among children and adolescents living in Northern Thailand: an implication for hepatitis A immunization. Sci Rep. 2023 Oct 13;13(1):17432. doi: 10.1038/s41598-023-44643-0.
• Background Ma F, Yang J, Kang G, Sun Q, Lu P, Zhao Y, Wang Z, Luo J, Wang Z. Comparison of the safety and immunogenicity of live attenuated and inactivated hepatitis A vaccine in healthy Chinese children aged 18 months to 16 years: results from a randomized, parallel controlled, phase IV study. Clin Microbiol Infect. 2016 Sep;22(9):811.e9-811.e15. doi: 10.1016/j.cmi.2016.06.004. Epub 2016 Jun 23.
• Background Liu XE, Wushouer F, Gou A, Kuerban M, Li X, Sun Y, Zhang J, Liu Y, Li J, Zhuang H. Comparison of immunogenicity between inactivated and live attenuated hepatitis A vaccines: a single-blind, randomized, parallel-group clinical trial among children in Xinjiang Uighur Autonomous Region, China. Hum Vaccin Immunother. 2013 Jul;9(7):1460-5. doi: 10.4161/hv.24366. Epub 2013 Apr 9.

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