Between 2020 and 2024, global COVID-19 vaccination efforts have prevented over 2.5 million deaths and preserved nearly 14.8 million years of life, according to a large-scale international study. The analysis, based on global data, reveals that for every 5,400 vaccine doses administered, one life was saved. In terms of longevity, one year of life was saved for every 900 doses.
The research assessed the full pandemic period, including the emergence and dominance of the Omicron variant, and measured both lives saved and life-years gained across various demographics. The vast majority of deaths prevented 82% occurred among individuals who received their vaccines before being infected. Notably, 57% of the vaccine’s protective effect was achieved during the Omicron wave, demonstrating the continued benefit of immunization even as the virus evolved.
Older adults saw the most substantial impact, with 90% of the prevented deaths and 76% of the life-years saved occurring in individuals aged 60 and above. This age group, which bore the highest burden of COVID-19 mortality, was therefore the primary beneficiary of the global vaccine rollout. In contrast, children and adolescents accounted for only 0.01% of lives saved and 0.1% of life-years gained, while young adults aged 20–29 contributed 0.07% and 0.3%, respectively.
Despite the known vulnerability of residents in long-term care facilities, they accounted for only 2% of the total life-years saved. This may reflect challenges in vaccine coverage, care infrastructure, or delayed access to vaccines for this population.
The study employed robust statistical modeling techniques to create a counterfactual scenario, estimating global mortality patterns had vaccines not been deployed. By comparing observed outcomes with this scenario, researchers were able to isolate and quantify the specific life-saving impact of COVID-19 vaccines.
While previous estimates of vaccine benefits often focused on the early pandemic phases or selected regions, this study offers a more conservative yet comprehensive picture of the enduring effect of vaccines. It underscores the critical role vaccination has played and continues to play in protecting the most vulnerable and reducing global COVID-19 mortality.
