Vaccination has long been a cornerstone of public health, and its impact is most visible in the reduction of childhood infectious diseases. Historically, childhood immunization programs have yielded enormous success in reducing the incidence of vaccine-preventable infections (VPI) such as measles, diphtheria, and polio. However, as the global population continues to age, the focus of immunization strategies is expanding to encompass adult and elderly populations. The development of vaccines for adults has become a crucial part of future healthcare strategies to reduce mortality and morbidity across the lifespan. Adult vaccination is no longer an afterthought, but a central component of healthy ageing planning and of the sustainability of healthcare systems.