B cell function and influenza vaccine responses in healthy aging and disease

• B cell defects increase with age and contribute to lower influenza vaccine response.
• Defects include lower Ig class switch recombination and activation-induced cytidine deaminase.
• T2D patients have high inflammation but do not have decreased vaccine response.
• HIV patients have high serum TNF-α, activated Tfh and lower vaccine response.
• Elderly CVD patients have decreased vaccine response.

Influenza vaccination is less effective in elderly as compared to young individuals. Several studies have addressed the identification of immune biomarkers able to monitor or predict a protective humoral immune response to the vaccine. In this review, we summarize these data, with emphasis on the effects of aging on influenza vaccine-specific B cell responses in healthy individuals and patients with Type-2 Diabetes, HIV and cardiovascular diseases.