Aging and vaccine responsiveness: determinants, dynamics and duration of antibody responses to pneumococcal and meningococcal vaccination in older adults

This thesis examines how ageing affects antibody responses after pneumococcal and meningococcal vaccination. Age-related immune changes increase older adults' risk of severe infections and contribute to weaker, less durable responses to vaccination. The research shows that vaccination can still protect older people, but the strength and quality of that protection decline with age. In particular, a reduced IgM antibody response appears linked to lower functional protection against pneumococci. It also finds considerable variation among older adults: some develop strong, long-lasting antibody responses, while others respond only to a limited extent. The findings are intended to improve understanding of how ageing influences vaccine responsiveness and to support vaccination strategies better suited to older adults' changing immune systems.