Global Estimates of Lives and Life-Years Saved by COVID-19 Vaccination During 2020-2024

Importance: Estimating 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, and lack crucial life-year calculations and often depend on strong modeling assumptions with unaccounted uncertainty. Objective: To calculate the lives and life-years saved by COVID-19 vaccination worldwide from the onset of the vaccination campaigns and until October 1, 2024. Design, Setting, and Participants: This comparative effectiveness study considered different strata of the worldwide population 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. Exposures: Any COVID-19 vaccination in any schedule and number of doses. Main Outcome Measure: Death. Results: In the main analysis, more than 2.5 million deaths were averted (1 death averted per 5400 vaccine doses administered). Eighty-two percent were among people vaccinated before any infection, 57% were during the Omicron period, and 90% pertained to people 60 years or older. Sensitivity analyses suggested 1.4 to 4.0 million lives were saved. Some sensitivity analyses showed a preponderance of the benefit during the pre-Omicron period. An estimated 14.8 million life-years were saved (1 life-year saved per 900 vaccine doses administered). The sensitivity range was 7.4 to 23.6 million life-years. Most life-years saved (76%) were among people 60 years or older, 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 aged 20 through 29 years (0.07% of lives saved and 0.3% of life-years saved) had very small contributions to the total benefit. Conclusions and Relevance: Estimates in this study 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 the years 2020-2024. Most benefits in lives and life-years saved was secured for a portion of older persons, a minority of the global population.