b型流感嗜血杆菌结合疫苗接种后婴幼儿安全性和免疫原性研究

Safety and immunogenicity in 3-5 months-old infants after primary and boosting immunization with Hib PRP-TT conjugate vaccine

目的评价b型流感嗜血杆菌结合疫苗（Hib—TT）安全性和免疫原性。方法分别采用Hib-TT试验疫苗和对照疫苗3针免疫接种3—5月龄婴幼儿，观察疫苗安全性，并采用定量ELISA法分别测定免疫前、免疫后和加强免疫后血清特异性IgG抗体浓度。结果实验疫苗和对照疫苗两组间不良反应总发生率（实验疫苗组为23．85％，对照疫苗组为31．40％）差异无统计学意义（χ2=0．5，P〉0．05），发热性总不良反应率分别为22．3％和31．3％，中、强发热反应率分别为3．67％和4．48％，差异无统计学意义；实验疫苗受试者局部红、肿、硬结等不良反应率为1．22％。实验疫苗3剂免疫后受试者血清抗Hib PRP IgG抗体平均几何浓度（GMC）为6．6786μg／ml，对照疫苗组血清抗体GMC为7．5346μg／ml，两组间抗体GMC差异无统计学意义（χ2=0．147，P=0．702）；加强免疫1剂后，实验疫苗组受试者血清抗体GMC从加强免疫前的2．6396μg／ml上升为6．2044μg/ml。结论实验疫苗接种3～5月龄婴幼儿具有良好的安全性。用间隔1个月、3剂次接种的基础免疫程序能诱导该年龄组受试者产生长期保护水平的血清特异性抗体，加强免疫1剂后能诱导机体产生免疫记忆反应。

Objectives To evaluate the safety and immunogenicity of Haemophilus influenzae type b capsular-tetanus toxoid（Hib-TT） conjugate vaccine. Methods In an open-controlled, randomized trial, the eligible and consented infants of 3 to 5 months-old received 3 doses of Hib-TT or a licensed Hib-TT conjugate vaccine （ Anerbao ） as the control vaccine to evaluate safety ; The serum anti-Hib PRP IgG antibody mean geometric concentration （GMC） in both groups after primary and boosting vaccination were measured by ELISA. Results No apparent difference in the frequency of total adverse reactions observed between two groups （ study vaccine 23.85% vs. comparator 31.40% ） （ χ2 =0.5, P〉0.05）. The mild and severe fever reaction of both vaccines was 3.67% and 4.48% respectively, with no significant difference. The local reactions including erythema, swelling and induration reported was 1.22% in study vaccine group. After 3 in- jections, the serum anti-Hib PRP IgG antibody GMC was 6.6686 μg/ml in study group and 7. 5346 μg/ml in control group, with no significant difference in both of the antibody GMC （χ2=0. 147, P=0. 702）. After one dose boosting injection, the serum antibody GMC in study group increased from 2. 6396 μg/ml of preboosting to 6.2044μg/ml of post-boosting. Conclusion The Hib-TT conjugate vaccine is proved to be safe in 3-5 months-old infants. The primary immune schedule for 3-5 months-old infants of 3 injections 1 month apart with the Hib-TT conjugate vaccine could induce IgG antibody response against Hib PRP with the GMC of long-term protection concentration in serum. A boosting dose after primary vaccination elicited obviously immunological memory.