WHO, as requested by its member states, launched the Expanded Programme on Immunization (EPI) in 1974 to make life-saving vaccines available to all globally. The modeling study published in The Lancet used a suite of mathematical and statistical models to estimate the global and regional public health impact of 50 years of vaccination against 14 pathogens in EPI.
Since 1974, vaccination has averted 154 million deaths, including 146 million among children younger than 5 years of whom 101 million were infants younger than 1 year. For every death averted, 66 years of full health were gained on average, translating to 10.2 billion years of full health gained. The study estimates that vaccination has accounted for 40% of the observed decline in global infant mortality, 52% in the African region.
Increased survival probability is observed even well into late adulthood. The results showed that, by estimation, in 2024, children aged 10 years are approximately 44% more likely to survive to their next birthday than if no vaccinations had occurred since 1974, individuals aged 25 years are 35% more likely, and those aged 50 years are 16% more likely. In terms of absolute impact, the Eastern Mediterranean and African regions have seen the largest vaccine-induced gains in life course survival probability since 1974, with the European region seeing the lowest absolute gains.
The researchers suggest continuous engagement of communities in vaccine uptake is crucial since hard won gains can so easily be lost. The next 50 years hold great promise, but need collective and sustained determination to deliver.
Recommendation resource:
1. Shattock AJ, Johnson HC, Sim SY, et al. Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization. Lancet. 2024 May 2:S0140-6736(24)00850-X.
2. World Health Assembly WHO expanded programme on immunization. 1974. https://iris.who.int/handle/10665/92778
3. Carter A, Msemburi W, Sim SY, et al. Modeling the impact of vaccination for the Immunization Agenda 2030: deaths averted due to vaccination against 14 pathogens in 194 countries from 2021 to 2030. Vaccine. 2023 doi: 10.1016/j.vaccine.2023.07.033. published online Aug 1
4. WHO Progress and challenges with achieving universal immunization coverage. 2023. https://www.who.int/publications/m/item/progress-and-challenges
