Understanding and improving vaccine efficacy in older adults.

Cellular aging of the immune system, commonly referred to as 'immunosenescence', drives a substantial decline in vaccine efficacy among older adults, who are already typically at a higher risk of reduced infection control. Therefore, preventive medicine requires novel strategies to improve vaccination in older adults, particularly by finding ways to mitigate immunosenescence and chronic inflammation. Here, we review how technical innovations, such as increased antigen amounts, improved adjuvants and mRNA-based and universal vaccines, can complement traditional methods of improving vaccination success in older adults. Furthermore, we discuss emerging clinical evidence suggesting that geroscience interventions, such as mTOR inhibition and caloric restriction, can enhance vaccine outcomes in older adults, potentially by targeting molecular aspects of immunosenescence and systemic characteristics of aging, including metabolic changes in the blood and chronic inflammation. Ultimately, we propose that integrating geroscience with tailored immunization could attenuate the effects of immune aging on vaccination efficacy in older populations.