Community Medicine Research Department, National Research Centre, Egypt.
Child Health Department, National Research Centre, Egypt.
Vaccine. 2018 Apr 5;36(15):2005-2011. doi: 10.1016/j.vaccine.2018.02.103. Epub 2018 Mar 9.
To evaluate early and long term anamnestic response to a booster dose of HBV vaccine among non-seroprotected children.
A national community based project was carried out on 3600 children aged 9 months to 16 years, fully vaccinated during infancy. They were recruited from 6 governorates representing Egypt. It revealed that 1535 children (42.8%) had non sero-protective anti-HBs (<10 IU/L) and were HBsAg or anti-HBc negative. A challenging dose of 10 μg of mono-valent Euvax HBV vaccine was given to 1121/1535 children. Quantitative assessment of anti-HBs was performed to detect early (2-4 weeks) and long term (one year) anamnestic responses.
Early anamnestic response developed among 967/1070 children (90.3%).Children having detectable anti-HBs (1-9 IU/L) significantly developed early anamnestic response (90%) compared to 85% with undetectable anti-HBs (<1 IU/L), P < 0.001. Multiple logistic analysis revealed that undetectable anti-HBs, living in rural residence and children aged 15-16 years were the most significant predicting risk factors for the absence of early anamnestic response (<10 IU/L), with AOR 2.7, 2.7 & 4.7 respectively. After one year, long term anamnestic response was absent among 15% of children who previously showed early response. Poor early anamnestic response and undetectable pre-booster anti-HBs were the significant predicting risk factors for absent long term anamnestic response, with AOR 18.7 & 2.7 respectively.
Immunological memory for HBV vaccine outlasts the presence of anti- HBs and HBV vaccination program provides effective long term protection even in children showing waning or undetectable concentrations of anti-HBs. This signifies no need for a booster dose especially to healthy children.
评估乙肝疫苗加强针在未产生免疫保护的儿童中的早期和长期记忆应答。
一项全国性的社区基础项目在 3600 名 9 个月至 16 岁、婴儿期全程接种疫苗的儿童中进行。他们来自代表埃及的 6 个省。结果显示，1535 名儿童（42.8%）未产生血清保护性抗-HBs（<10IU/L），且 HBsAg 和抗-HBc 均为阴性。对 1121/1535 名儿童给予 10μg单价 Euvax HBV 疫苗进行挑战剂量接种。定量检测抗-HBs，以检测早期（2-4 周）和长期（1 年）记忆应答。
在 1070 名儿童中有 967 名（90.3%）出现早期记忆应答。有可检测抗-HBs（1-9IU/L）的儿童明显比无可检测抗-HBs（<1IU/L）的儿童（90%比 85%）更早出现记忆应答，P<0.001。多因素逻辑分析显示，无可检测抗-HBs、居住在农村和 15-16 岁儿童是早期记忆应答缺失（<10IU/L）的最显著预测危险因素，其 OR 值分别为 2.7、2.7 和 4.7。一年后，15%之前出现早期应答的儿童出现长期记忆应答缺失。早期记忆应答不良和预加强针前无可检测抗-HBs是长期记忆应答缺失的显著预测危险因素，OR 值分别为 18.7 和 2.7。
HBV 疫苗的免疫记忆持续存在于抗-HBs 之外，乙肝疫苗接种计划即使在抗-HBs 浓度下降或无法检测到的儿童中也能提供有效的长期保护。这表明不需要加强针，特别是对健康儿童。
