Lolekha Somsak, Pratuangtham Surasak, Punpanich Warunee, Bowonkiratikachorn Piyaporn, Chimabutra Kanittha, Weber Françoise
Ramathibodi Hospital, Bangkok, Thailand.
J Trop Pediatr. 2003 Dec;49(6):333-9. doi: 10.1093/tropej/49.6.333.
As fewer children in Thailand are exposed to hepatitis A virus (HAV) and so do not have seroprotective anti-HAV antibodies, they are becoming an important source of HAV transmission. A flexible HAV vaccination schedule would facilitate incorporation of the vaccine into existing immunization programmes, and we compared the immunogenicity and safety of three HAV immunization schedules. An open, randomized, clinical trial was carried out in which healthy children were given a primary dose of the inactivated hepatitis A vaccine, Avaxim 80 paediatric, with a booster dose 6, 12 or 18 months later. Anti-HAV geometric mean concentrations (GMC), seroconversion rates, and GMC ratios (GMCR) of the three schedules were compared and reactogenicity was evaluated. Seroconversion rates were above 98 per cent (per group) up to the booster. The three schedules were equivalent in terms of GMCRs, each eliciting a large booster effect. Local reactions were reported for fewer than 9 per cent of each group after dose one and less frequently after the booster dose. Injection site pain, gastrointestinal tract disorders and fever were the most commonly reported adverse events. No vaccine-related serious adverse events were reported. It was concluded that the hepatitis A vaccine, Avaxim 80 paediatric, is safe and immunogenic when given as a two-dose schedule to healthy seronegative children aged 5-10 years, with the second dose given at either 6, 12 or 18 months after the first.
由于泰国接触甲型肝炎病毒（HAV）的儿童减少，因此没有血清保护性抗-HAV抗体，他们正成为HAV传播的重要来源。灵活的HAV疫苗接种计划将有助于将该疫苗纳入现有的免疫规划，我们比较了三种HAV免疫接种计划的免疫原性和安全性。开展了一项开放、随机临床试验，给健康儿童接种一剂灭活甲型肝炎疫苗Avaxim 80儿科剂型，在6、12或18个月后接种加强剂量。比较了三种接种计划的抗-HAV几何平均浓度（GMC）、血清转化率和GMC比值（GMCR），并评估了反应原性。在接种加强剂量之前，每组的血清转化率均高于98%。三种接种计划的GMCR相当，每种计划都产生了较大的加强效果。每组在第一剂后报告局部反应的不到9%，在加强剂量后报告频率更低。注射部位疼痛、胃肠道疾病和发热是最常报告的不良事件。未报告与疫苗相关的严重不良事件。得出的结论是，对于5至10岁健康的血清阴性儿童，以两剂方案接种Avaxim 80儿科剂型甲型肝炎疫苗是安全且具有免疫原性的，第二剂在第一剂后的6、12或18个月接种。
