Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Nopparat Rajathanee Hospital, Ministry of Public Health, Bangkok, Thailand.
Hum Vaccin Immunother. 2022 Dec 31;18(1):2028513. doi: 10.1080/21645515.2022.2028513. Epub 2022 Feb 1.
Japanese encephalitis is the main cause of viral encephalitis in Asia. In a previous single-arm vaccine trial, an inactivated chromatographically purified Japanese encephalitis Vero cell vaccine (CVI-JE; JEVAC) was safe and immunogenic in 152 Thai children aged 1-3 years receiving a 2-dose primary immunization and booster dose 1 year later. We conducted a 5-year follow-up assessment of the persistence of the immune response the 144 children remaining in this cohort after first booster dose. Immunity was assessed by 50% plaque reduction neutralization test annually for up to 5 years post-booster. Seroprotection rates (95%CI) decreased from 100% (97.1-100) at 1 year post-booster to 93% (85.0-98.3) at 5 years post-booster. No serious vaccine-related adverse events or Japanese encephalitis infections were reported. A 2-dose primary immunization and booster 1 year later with CVI-JE provided long-lasting immunity in the majority of children.
日本脑炎是亚洲病毒性脑炎的主要病因。在之前的一项单臂疫苗试验中，152 名 1-3 岁的泰国儿童接受了 2 剂基础免疫和 1 年后的加强针，使用了经色谱纯化的日本脑炎vero 细胞灭活疫苗（CVI-JE；JEVAC），结果显示该疫苗是安全且具有免疫原性的。我们对该队列中 144 名在初次加强针后仍留在研究中的儿童进行了 5 年的免疫应答持久性随访评估。在加强针后最多 5 年内，每年通过 50%蚀斑减少中和试验评估免疫情况。加强针后 1 年的血清保护率（95%CI）从 100%（97.1-100）下降到 5 年时的 93%（85.0-98.3）。未报告与疫苗相关的严重不良事件或日本脑炎感染。2 剂基础免疫和 1 年后加强针接种 CVI-JE 为大多数儿童提供了持久的免疫力。
