Estimating global lives and life-years saved is important to put into perspective the benefits of COVID-19 vaccination, say Ioannidis, et al. (2025) who add that 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. The researchers sought to calculate the lives and life-years saved by COVID-19 vaccination worldwide from the onset of the vaccination campaigns and until Oct. 1, 2024.

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.

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.

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.

Reference: Ioannidis JPA, et al. Global Estimates of Lives and Life-Years Saved by COVID-19 Vaccination During 2020-2024.
JAMA Health Forum. Vol. 6, No. 7. 2025;6;(7):e252223. doi:10.1001/jamahealthforum.2025.2223