Individuals over the age of 65 comprise a substantial portion of the world population and become more susceptible to vaccine-preventable infections with age as vaccination response diminishes. The underlying reason for this impaired vaccine response in older individuals is not entirely clear. We evaluated potential differences in phenotypic and functional responses of B cells from healthy younger (22–45 years) and older (64–95 years) individuals that may associate with a diminished antibody response to influenza vaccination. We report that age is associated with expansion of atypical memory B cells (CD10⁻CD20⁺CD21⁻CD27⁻) and an age-associated B cell (ABC, CD21⁻T-bet⁺CD11c⁺) phenotype. Reduced expression of PAX5 was also seen in older individuals. Poor influenza-specific antibody production following vaccination was associated with low PAX5 expression and a distinct composition of the ABC compartment. Collectively, these findings demonstrate that the characteristics of the ABC populations of older individuals are associated with antibody production following influenza vaccination.

65 岁以上的人占世界人口的很大一部分，并且随着疫苗接种反应的减弱，随着年龄的增长，他们更容易感染疫苗可预防的感染。老年人疫苗反应受损的根本原因尚不完全清楚。我们评估了来自健康的年轻（22-45 岁）和年长（64-95 岁）个体的 B 细胞表型和功能反应的潜在差异，这些差异可能与对流感疫苗接种的抗体反应减弱有关。^{我们报告说，年龄与非典型记忆 B 细胞 (CD10 −} CD20 ⁺ CD21 ⁻ CD27 ⁻ ) 和年龄相关 B 细胞 (ABC, CD21 ⁻ T-bet ⁺ CD11c ) 的扩增有关⁺）表型。PAX5 的表达减少也见于老年人。疫苗接种后流感特异性抗体产生不良与 PAX5 表达低和 ABC 区室的独特组成有关。总的来说，这些发现表明，老年人 ABC 人群的特征与流感疫苗接种后的抗体产生有关。