Findlow Helen, Sow Samba, Borrow Ray, Tapia Milagritos, Haidara Fadima Cheick, Akinsola Adebayo K, Idoko Olubukola T, Diallo Fatoumata, Adegbola Richard, Tang Yuxiao, Parulekar Varsha, Chadha Helen, Mabey Lesley, Holme Daniel, Townsend Kelly, Chaumont Julie, Laforce F Marc, Kulkarni Prasad S, Marchetti Elisa, Viviani Simonetta, Hassan-King Musa, Preziosi Marie-Pierre
Vaccine Evaluation Unit, Health Protection Agency North West, P.O. Box 209, Clinical Sciences Building, Manchester Royal Infirmary, Manchester M13 9WZ, United Kingdom.
Clin Vaccine Immunol. 2011 Sep;18(9):1492-6. doi: 10.1128/CVI.05020-11. Epub 2011 Jul 13.
A phase II clinical study was conducted in African toddlers (aged 12 to 23 months), with subjects receiving either investigational meningococcal group A conjugate (PsA-TT), meningococcal ACWY polysaccharide (PsACWY), or Haemophilus influenzae type b (Hib-TT) vaccine. Ten months following vaccination, the 3 study groups were further randomized to receive a dose of PsA-TT, a 1/5 dose of PsACWY, or a dose of Hib-TT vaccine. Group A serum bactericidal antibody (SBA) results have been reported previously, with PsA-TT demonstrating superior immunogenicity versus PsACWY vaccine. Immunogenicity for serogroups W135 and C was assessed by SBA assay to investigate the impact of multiple doses in this age group. Blood samples were taken prior to vaccination, 28 days and 40 weeks post-primary vaccination, and 7 and 28 days post-booster vaccination with a 1/5 dose of PsACWY. Subjects who had previously received a full dose of PsACWY had W135 SBA geometric mean titers (GMTs) of 26.1 and 4.4 at 7 and 28 days post-booster vaccination with a 1/5 PsACWY dose, respectively, whereas the W135 SBA GMTs of naïve subjects at these time points following vaccination with a 1/5 dose of PsACWY were 861.1 and 14.6, respectively. Similar differences were observed for serogroup C, with SBA GMTs of 99 and 5.9 at 7 and 28 days post-booster vaccination with a 1/5 dose of PsACWY, respectively, for naïve subjects, compared to 4.1 and 3.2 for previously vaccinated subjects. Immunologic hyporesponsiveness for groups C and W135 was observed following a full dose of PsACWY vaccine at 12 to 23 months of age and a 1/5 dose of PsACWY 10 months later compared to the case for PsACWY-naïve subjects receiving a 1/5 dose of PsACWY vaccine.
在非洲幼儿（12至23个月大）中进行了一项II期临床研究，受试者分别接受研究性A群脑膜炎球菌结合疫苗（PsA-TT）、ACWY群脑膜炎球菌多糖疫苗（PsACWY）或b型流感嗜血杆菌疫苗（Hib-TT）。接种疫苗10个月后，3个研究组进一步随机分组，分别接受一剂PsA-TT、1/5剂量的PsACWY或一剂Hib-TT疫苗。A组血清杀菌抗体（SBA）结果此前已有报道，PsA-TT显示出比PsACWY疫苗更强的免疫原性。通过SBA检测评估W135群和C群的免疫原性，以研究该年龄组多剂疫苗的影响。在接种疫苗前、初次接种疫苗后28天和40周以及用1/5剂量的PsACWY进行加强免疫接种后7天和28天采集血样。之前接受过全剂量PsACWY的受试者在接受1/5剂量PsACWY加强免疫接种后7天和28天的W135 SBA几何平均滴度（GMT）分别为26.1和4.4，而初次接种1/5剂量PsACWY疫苗的受试者在这些时间点的W135 SBA GMT分别为861.1和14.6。C群也观察到类似差异，初次接种疫苗的受试者在接受1/5剂量PsACWY加强免疫接种后7天和28天的SBA GMT分别为99和5.9，而之前接种过疫苗的受试者分别为4.1和3.2。与初次接种1/5剂量PsACWY疫苗的受试者相比，12至23个月龄时接受全剂量PsACWY疫苗且10个月后接受1/5剂量PsACWY疫苗的受试者，C群和W135群出现了免疫低反应性。
