BACKGROUND In Thailand, the hepatitis B (HB) vaccine is administered as a tetravalent vaccine (DTwP-HB) to all infants at 2, 4, and 6 months of age, following an initial vaccination with a monovalent HB vaccine at birth. As part of ongoing vaccine evaluation, we aimed to compare the hepatitis B immunogenicity profiles of children who had received either the pentavalent (DTwP-HB-Hib) or the hexavalent (DTaP-HB-Hib-IPV) vaccine. METHODS Two groups of infants, whose mothers previously received the tetanus-diphtheria-acellular pertussis vaccine (Tdap), were randomly vaccinated with either pentavalent or hexavalent vaccine at 2, 4, 6, and 18 months of age, following monovalent HB vaccine at birth. Blood samples were obtained at birth, one-month post-primary series immunization (mo 7), pre-booster (mo 18), one-month post-booster (mo 19), and six months post-booster (mo 24). The third group of infants, whose mothers did not receive Tdap, was vaccinated with DTwP-HB-Hib (EPI pentavalent group). Levels of HBsAg, anti-HBc, and anti-HBs were evaluated by means of an automated Chemiluminescent Microparticle Immunoassay. RESULTS Anti-HBs levels of ≥10 mIU/ml were achieved in 99.2% (hexavalent group), 99.2% (pentavalent group), and 98.5% (EPI pentavalent group) of infants, after four-dose immunization (at 0, 2, 4, 6 months of age). One month after the additional dose given at 18 months of age, anti-HBs levels of ≥10 mIU/ml were observed in 100% (hexavalent group), 99.2% (pentavalent group), and 93.8% (EPI pentavalent group) of infants. At 24 months of age, higher percentages of infants achieving anti-HBs levels ≥10 mIU/ml were found in the hexavalent group (98.3%) compared to the pentavalent group (86.5%). CONCLUSIONS Both vaccines were effective in inducing anti-HBs levels of ≥10 mIU/ml, and therefore either can be used as a single formula booster at 18 months of age to simplify vaccine administration under the Expanded Program on Immunization in Thailand.

中文翻译：

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在分别接种2、4、6和18个月大的婴儿后，分别于DTwP-HB-Hib和六价DTaP-HB-Hib-IPV疫苗诱导的乙型肝炎表面抗体水平比较出生。

背景技术在泰国，在出生时初次接种单价HB疫苗后，向所有2、4、6个月大的婴儿以四价疫苗（DTwP-HB）的形式接种乙型肝炎疫苗。作为正在进行的疫苗评估的一部分，我们旨在比较接受五价（DTwP-HB-Hib）或六价（DTaP-HB-Hib-IPV）疫苗的儿童的乙型肝炎免疫原性。方法两组婴儿，其母亲此前曾接种过破伤风-白喉无细胞百日咳疫苗（Tdap），在出生时接种了单价HB疫苗后，分别于2、4、6和18个月时随机接种了五价或六价疫苗。在出生时，初次系列免疫后一个月（mo 7），加强免疫前（mo 18），加强免疫一个月（mo 19），和加强后六个月（mo 24）。母亲未接受Tdap的第三组婴儿接种了DTwP-HB-Hib疫苗（EPI五价组）。HBsAg，抗-HBc和抗-HBs的水平通过自动化学发光微粒免疫测定法进行评估。结果在四剂免疫接种后（0、2、0、2、3、9、9、12、5、9），婴儿的抗HBs水平达到≥10mIU / ml。 4、6个月大）。在18个月大的婴儿额外服药一个月后，在100％（六价组），99.2％（五价组）和93.8％（EPI五价组）的婴儿中观察到抗HBs≥10 mIU / ml。 。在六价组中，发现24个月大的婴儿中抗HBs≥10 mIU / ml的比例更高（98。3％），而五价组（86.5％）。结论两种疫苗均可有效诱导≥10 mIU / ml的抗HBs水平，因此根据泰国《扩大免疫规划》，两种疫苗均可在18个月大时用作单一配方的增强剂，以简化疫苗的管理。