Adult Immunization in 2025

Abstract

Immunization represents one of the most significant achievements in medicine. Over the past 50 years, vaccines have prevented more deaths in Canada than any other public health intervention. Routine childhood immunization programs have dramatically reduced the incidence of highly transmissible infections, such as measles, mumps, rubella, and varicella. Furthermore, vaccination efforts have led to the global eradication of smallpox and the near elimination of poliomyelitis. However, declining vaccination coverage has facilitated the re‑emergence of vaccine-preventable diseases, as evidenced by the ongoing resurgence of measles outbreaks worldwide.

Vaccination is the most effective and durable intervention for the prevention of numerous infectious diseases. Immunization programs provide substantial benefits for patients and communities from potentially life-threatening infectious diseases. Early-life vaccination is essential for children to develop robust immunity. Furthermore, immunization remains a critical preventive measure in older adults who exhibit increased vulnerability to infection and a higher likelihood of severe outcomes, including complications, hospitalizations, and deaths. The objective of this review is to provide information on immunization across all age groups and at‑risk populations.