Global estimates of lives and life-years saved by COVID-19 vaccination during 2020-2024

ImportanceEstimating global lives and life-years saved is important to put into perspective the benefits of COVID-19 vaccination. Prior studies have focused mainly on the pre-Omicron period or only on specific regions, lack crucial life-year calculations, and often depend on strong modeling assumptions with unaccounted uncertainty. ObservationsWe aimed to calculate the lives and life-years saved by COVID-19 vaccination worldwide from the onset of the vaccination campaigns and until October 2024. We considered different strata according to age; community-dwelling and long-term care residence status; pre-Omicron and Omicron periods; and vaccination before and after a SARS-CoV-2 infection. In the main analysis, 2.533 million deaths were averted (1 death averted per 5,400 vaccine doses administered). Eighty-two percent were among people vaccinated before any infection, 57% were in the Omicron period, and 90% pertained to people 60 years and above. Sensitivity analyses suggested 1.4 to 4.0 million lives saved. Some sensitivity analyses showed preponderance of the benefit during the pre-Omicron period. We estimated 14.8 million life-years saved (1 life-year saved per 900 vaccine doses administered). Sensitivity range was 7.4-23.6 million life-years. Most life-years saved (76%) were in people over 60 years old, but long-term care residents contributed only 2% of the total. Children and adolescents (0.01% of lives saved and 0.1% of life-years saved) and young adults 20-29 years old (0.07% of lives saved and 0.3% of life-years saved) had very small contributions to the total benefit. Conclusions and relevanceBased on a number of assumptions, these estimates are substantially more conservative than previous calculations focusing mostly on the first year of vaccination, but they still clearly demonstrate a major overall benefit from COVID-19 vaccination during 2020-2024. The vast majority of benefit in lives and life-years saved was secured for a portion of the elderly minority of the global population.