Ramirez Alejandro, Co Mary, Mathew Anuja
Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America.
PLoS One. 2016 Mar 2;11(3):e0150425. doi: 10.1371/journal.pone.0150425. eCollection 2016.
Several studies have shown a reduced efficacy of influenza vaccines in the elderly compared to young adults. In this study, we evaluated the immunogenicity and protective efficacy of a commercially available inactivated influenza vaccine (Fluzone®) in young adult and aged mice. C57/BL6 mice were administered a single or double immunization of Fluzone® with or without CpG and challenged intranasally with H1N1 A/California/09 virus. A double immunization of Fluzone® adjuvanted with CpG elicited the highest level of protection in young adult mice which was associated with increases in influenza specific IgG, elevated HAI titres, reduced viral titres and lung inflammation. In contrast, the vaccine schedule which provided fully protective immunity in young adult mice conferred limited protection in aged mice. Antigen presenting cells from aged mice were found to be less responsive to in vitro stimulation by Fluzone and CpG which may partially explain this result. Our data are supportive of studies that have shown limited effectiveness of influenza vaccines in the elderly and provide important information relevant to the design of more immunogenic vaccines in this age group.
多项研究表明，与年轻人相比，流感疫苗在老年人中的效力有所降低。在本研究中，我们评估了一种市售灭活流感疫苗（Fluzone®）在年轻成年小鼠和老年小鼠中的免疫原性和保护效力。给C57/BL6小鼠单次或两次接种Fluzone®，接种时添加或不添加CpG，然后经鼻用H1N1 A/加利福尼亚/09病毒进行攻击。用CpG佐剂进行两次接种Fluzone®在年轻成年小鼠中引发了最高水平的保护，这与流感特异性IgG增加、血凝抑制（HAI）效价升高、病毒滴度降低和肺部炎症减轻有关。相比之下，在年轻成年小鼠中提供完全保护性免疫的疫苗接种方案在老年小鼠中提供的保护有限。发现老年小鼠的抗原呈递细胞对Fluzone和CpG的体外刺激反应较弱，这可能部分解释了这一结果。我们的数据支持了那些表明流感疫苗在老年人中效力有限的研究，并为设计该年龄组中更具免疫原性的疫苗提供了重要信息。
