Higgins Rachel A, Temple Beth, Dai Vo Thi Trang, Phan Thanh V, Toan Nguyen Trong, Spry Leena, Toh Zheng Quan, Nation Monica L, Ortika Belinda D, Uyen Doan Y, Cheung Yin Bun, Nguyen Cattram D, Bright Kathryn, Hinds Jason, Balloch Anne, Smith-Vaughan Heidi, Huu Tran Ngoc, Mulholland Kim, Satzke Catherine, Licciardi Paul V
Infection and Immunity, Murdoch Children's Research Institute, Melbourne, Australia.
Global Health, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia.
Lancet Reg Health West Pac. 2021 Sep 20;16:100273. doi: 10.1016/j.lanwpc.2021.100273. eCollection 2021 Nov.
This study investigated the immunogenicity and impact on nasopharyngeal carriage of a single dose of PCV10 given to 18-month-old Vietnamese children. This information is important for countries considering catch-up vaccination during PCV introduction and in the context of vaccination during humanitarian crises.
Two groups of PCV-naïve children within the Vietnam Pneumococcal Project received PCV10 (n=197) or no PCV (unvaccinated; n=199) at 18 months of age. Blood samples were collected at 18, 19, and 24 months of age, and nasopharyngeal swabs at 18 and 24 months of age. Immunogenicity was assessed by measuring serotype-specific IgG, opsonophagocytosis (OPA) and memory B cells (Bmem). Pneumococci were detected and quantified using real-time PCR and serotyped by microarray.
At 19 months of age, IgG and OPA responses were higher in the PCV10 group compared with the unvaccinated group for all PCV10 serotypes and cross-reactive serotypes 6A and 19A. This was sustained out to 24 months of age, at which point PCV10-type carriage was 60% lower in the PCV10 group than the unvaccinated group. Bmem levels increased between 18 and 24 months of age in the vaccinated group.
We demonstrate strong protective immune responses in vaccinees following a single dose of PCV10 at 18 months of age, and a potential impact on herd protection through a substantial reduction in vaccine-type carriage. A single dose of PCV10 in the second year of life could be considered as part of catch-up campaigns or in humanitarian crises to protect children at high-risk of pneumococcal disease.
本研究调查了给18月龄越南儿童接种单剂10价肺炎球菌结合疫苗（PCV10）的免疫原性及其对鼻咽部肺炎球菌携带情况的影响。该信息对于考虑在引入PCV期间进行补种疫苗以及在人道主义危机期间进行疫苗接种的国家而言至关重要。
越南肺炎球菌项目中两组未接种过PCV的儿童在18月龄时分别接种PCV10（n = 197）或不接种PCV（未接种疫苗组；n = 199）。在18、19和24月龄时采集血样，在18和24月龄时采集鼻咽拭子。通过测量血清型特异性IgG、吞噬杀菌作用（OPA）和记忆B细胞（Bmem）评估免疫原性。使用实时PCR检测并定量肺炎球菌，并通过微阵列进行血清分型。
在19月龄时，PCV10组中所有PCV10血清型以及交叉反应血清型6A和19A的IgG和OPA反应均高于未接种疫苗组。这种情况持续到24月龄，此时PCV10组中PCV10型携带率比未接种疫苗组低60%。接种疫苗组的Bmem水平在18至24月龄之间有所增加。
我们证明，18月龄儿童接种单剂PCV10后，疫苗接种者体内会产生强烈的保护性免疫反应，并且通过大幅降低疫苗型携带率对群体保护产生潜在影响。在儿童生命的第二年接种单剂PCV10可被视为补种活动的一部分，或在人道主义危机中用于保护面临肺炎球菌疾病高风险的儿童。
