As life expectancy continues to rise, the proportion of older individuals is increasing rapidly, leading to significant global health challenges. Older adults have a greater risk of serious illness due to infectious diseases, but often exhibit poor responses to vaccines, raising concerns about how to effectively protect this population.
In this thesis of Alper Çevirgel, we focused on understanding inter-individual immune variation and its impact on vaccine responsiveness during ageing. By studying a cohort spanning various age groups, we investigated key factors that are associated with vaccine responsiveness. Our study combines advanced immunological methods with high-dimensional data analysis and novel perspectives to identify biological ageing factors that contribute to reduced vaccine responses. We identified immunotypes that represent distinct immune cell subset compositions which explained immune variation better than chronological age and were associated with responsiveness to multiple vaccines. Importantly, by summarizing the perturbations of the immune cell subset network, we identified potential biomarkers that could allow for the early detection of poor vaccine responders.
These insights not only advance our understanding of immunosenescence, the gradual deterioration of the immune system with age but also provide a foundation for more personalized/targeted vaccine strategies aimed at improving protection against infectious diseases in subgroups of higher risk older adults.
