Division of Infectious Diseases and Respiratory Medicine, Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
Division of Behavioral Science, National Defense Medical College Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
Vaccine. 2023 Sep 22;41(41):5974-5978. doi: 10.1016/j.vaccine.2023.08.030. Epub 2023 Aug 22.
The effect of the timing of additional doses and the long-term persistence of lyophilized inactivated tissue culture hepatitis A (HA) vaccine (Aimmugen®) on antibodies is unknown.
A single-center, cross-sectional, observational study was conducted in collaboration with the Japan Air Self-Defense Force, whose personnel were immunized with Aimmugen® when deployed to endemic areas. Patients who consented to this study after a medical examination with blood sampling between June 2022 and February 2023 were included; HA-IgG level in the residual serum was measured using the chemiluminescent immunoassay method. The exact vaccination history was investigated based on immunization records maintained by the Ministry of Defense, and a questionnaire was used to collect confounding factors.
Of the 181 participants observed, 49 were in the unvaccinated group, and 132 were in the vaccinated group. Out of the vaccinated group, 6.8 % received either one or two doses, 40.9 % received three doses, and 52.3 % received more than four doses. IgG antibody titers (S/CO value) in each group (0, 1 or 2, 3, and over 4) increased in a frequency-dependent manner, with those vaccinated over four times showing significantly higher IgG antibody titers than all other groups (0.19 ± 0.10 vs 3.66 ± 3.00 vs 7.63 ± 3.57 vs 10.57 ± 1.86, respectively). When the number of months elapsed from the last vaccination to the date of blood collection in each group was plotted against IgG antibody titer, the slope of the regression line flattened out from a decreasing trend in the order 1 or 2, 3, over 4.
Three doses of Aimmugen® are efficacious, but four or more doses induce more robust and sustained antibody production. Additionally, four or more doses may be effective when there is a need to ensure long-term immunity or risk of prolonged exposure.
冻干细胞培养甲型肝炎（HA）灭活疫苗（Aimmugen®）的追加剂量时间和长期持久性对抗体的影响尚不清楚。
本研究是与日本航空自卫队合作进行的一项单中心、横断面、观察性研究，该部队人员在部署到流行地区时接种 Aimmugen®。2022 年 6 月至 2023 年 2 月期间，在体检并采集血样后同意参加本研究的患者被纳入研究；使用化学发光免疫分析法检测剩余血清中的 HA-IgG 水平。根据国防部保存的免疫接种记录调查确切的接种史，并使用问卷收集混杂因素。
在观察的 181 名参与者中，49 名未接种组，132 名接种组。在接种组中，6.8%接种了 1 剂或 2 剂，40.9%接种了 3 剂，52.3%接种了 4 剂以上。每组（0、1 或 2、3 和 4 以上）的 IgG 抗体滴度（S/CO 值）均呈频率依赖性增加，接种 4 剂以上组的 IgG 抗体滴度显著高于其他所有组（分别为 0.19±0.10 vs 3.66±3.00 vs 7.63±3.57 vs 10.57±1.86）。当每组从最后一次接种到采血日期的月数与 IgG 抗体滴度相关时，回归线的斜率从 1 或 2、3、4 以上的递减趋势趋于平稳。
Aimmugen®接种 3 剂有效，但接种 4 剂或更多剂可诱导更强大和持久的抗体产生。此外，当需要确保长期免疫力或有长时间暴露的风险时，4 剂或更多剂可能是有效的。
