Ying Chen1, Chen-Liang Zhou2, Xin-Jiang Zhang3, Zhi-Yong Hao3, Yan-Hong Zhang3, Song-Mei Wang4, Jing-Chen Ma5, Gan Zhao2, Chao Qiu1, Yu-Liang Zhao5, Bin Wang6, Xuan-Yi Wang7. 1. Key Laboratory of Medical Molecular Virology of MoE & MoH, and Institutes of Biomedical Sciences, Fudan University, Shanghai, China. 2. Key Laboratory of Medical Molecular Virology of MoE & MoH, School of Basic Medical Sciences, Fudan University, Shanghai, China. 3. Zhengding County Center for Disease Control and Prevention, Zhengding, Hebei, China. 4. Laboratory of Molecular Biology, Training Center of Medical Experiments, School of Basic Medical Sciences, Fudan University, Shanghai, China. 5. Hebei Province Center for Disease Control and Prevention, Shijiazhuang, Hebei, China. 6. Key Laboratory of Medical Molecular Virology of MoE & MoH, School of Basic Medical Sciences, Fudan University, Shanghai, China. Electronic address: bwang3@fudan.edu.cn. 7. Key Laboratory of Medical Molecular Virology of MoE & MoH, and Institutes of Biomedical Sciences, Fudan University, Shanghai, China. Electronic address: xywang@shmu.edu.cn.
Abstract
BACKGROUND: In recent years, hepatitis A virus (HAV) infection has declined considerably in China, associated with wide deployment of HAV vaccines and improvement in socio-economic indicators. Towards the elimination of HA in the country, we assessed the duration and characteristics of immunity conferred by the widely used, locally manufactured HAV vaccine. METHODS: This is a longitudinal cohort study that followed recipients of a live attenuated HAV vaccine 17 years after the initial administration. Blood samples were collected from participants pre- and two-week post-booster HAV vaccine dose. Serum anti-HAV antibody was measured by ELISA method. Memory B and T cells were determined by ELISPOT and Flow Cytometry assays, respectively. RESULTS: A robust anamnestic response was observed two-week post-challenge. Both HAV-specific memory B cell and T cells remained, and responded quickly when re-encountering HAV. The magnitude of recall responses was present, regardless of the status of the serum anti-HAV antibody pre-booster. CONCLUSIONS: We demonstrated long-term immunity from the live attenuated HAV vaccine, including antibody persistence and immunological memory. Considering the conditions that make elimination of infectious diseases feasible, following polio, hepatitis A could be targeted for elimination in China.
BACKGROUND: In recent years, hepatitis A virus (HAV) infection has declined considerably in China, associated with wide deployment of HAV vaccines and improvement in socio-economic indicators. Towards the elimination of HA in the country, we assessed the duration and characteristics of immunity conferred by the widely used, locally manufactured HAV vaccine. METHODS: This is a longitudinal cohort study that followed recipients of a live attenuated HAV vaccine 17 years after the initial administration. Blood samples were collected from participants pre- and two-week post-booster HAV vaccine dose. Serum anti-HAV antibody was measured by ELISA method. Memory B and T cells were determined by ELISPOT and Flow Cytometry assays, respectively. RESULTS: A robust anamnestic response was observed two-week post-challenge. Both HAV-specific memory B cell and T cells remained, and responded quickly when re-encountering HAV. The magnitude of recall responses was present, regardless of the status of the serum anti-HAV antibody pre-booster. CONCLUSIONS: We demonstrated long-term immunity from the live attenuated HAV vaccine, including antibody persistence and immunological memory. Considering the conditions that make elimination of infectious diseases feasible, following polio, hepatitis A could be targeted for elimination in China.