Singapore’s rapidly ageing population faces a growing threat from vaccine-preventable diseases (VPDs) such as respiratory syncytial virus (RSV) and herpes zoster (HZ), and this is driven by age-related decline in immunity (ARDI) and high rates of chronic comorbidities. Despite the success of Singapore’s childhood immunisation programmes, adult immunisation rate remains poor. Emerging evidence highlights the long-term health and economic consequences of VPDs in older adults, underscoring the urgent need for proactive prevention. Adjuvanted vaccines, including novel RSV and HZ vaccines, have shown potential in enhancing immune responses, mitigating the effects of ARDI, extending protection duration, and restoring cellular immunity in older adults to levels observed in younger populations. With the availability of such vaccines and potential future government subsidies, adult immunisation should be integrated into routine care. Effective patient counselling and a standardised vaccination checklist can help to improve uptake and reduce the burden of VPDs in Singapore’s ageing society.