- COVID-19 vaccination prevented an estimated 2.5 million deaths globally from December 2020 to October 2024.
- People ages 60 years and older accounted for nearly 90% of that mortality benefit.
- Children and adolescents ages 19 and younger made up only 0.01% of the estimated total lives saved.
While the worldwide rollout of COVID-19 vaccinations saved millions of lives, benefits were mostly seen in older adults, according to a comparative effectiveness study.
COVID vaccination prevented an estimated 2.5 million deaths globally from December 2020 to October 2024, with lives saved among people ages 60 and older accounting for nearly 90% of that mortality benefit, reported researchers led by John Ioannidis, MD, DSc, of Stanford University School of Medicine in California.
Children and adolescents ages 19 and younger made up only 0.01% of the estimated total lives saved by vaccination, with young adults ages 20 to 29 accounting for another 0.07% of saved lives, the authors noted in JAMA Health Forum.
Vaccination also delivered an estimated 14.8 million life-years saved worldwide, with the benefits again skewed heavily to older people. Those ages 60 and older accounted for three-quarters (75.9%) of that life-years benefit, while people ages 40 through 59 were responsible for 20.5% of preserved life-years.
Those ages 0 to 29 years enjoyed 0.4% of the life-year benefits. Only 2% of the saved life-years belonged to long-term care residents.
"This study found that COVID-19 vaccination offered major benefits during 2020-2024," Ioannidis and team wrote, adding that vaccination benefits in lives and life-years saved "seem to be largely limited to the portion of the global population that are older," a group with higher infection rates and greater early vaccine coverage.
Their estimate of lives saved is lower than prior analyses, and the study also did not address virus-related hospitalizations. A Commonwealth Fund estimate from 2022 put the number of lives saved by COVID vaccination in the U.S. alone at 3.2 million from December 2020 to November 2022, along with 18 million associated hospitalizations averted. Meanwhile, a Lancet Respiratory Medicine study estimated 1.6 million lives saved in Europe from December 2020 to March 2023 among people ages 25 and older.
In an accompanying invited commentary, Monica Gandhi, MD, MPH, of the University of California San Francisco, noted that the new study reinforced the "steep age gradient" in COVID-19 vaccination benefits.
The finding that "older people were to benefit most from vaccination and protection suggested that we could have taken an approach to the pandemic in the U.S. that was more in line with harm reduction principles: protect those who need protection but minimize the harm of blanket restrictions to those who are at lower risk," Gandhi wrote.
"At this point, a risk-based vaccination approach to boosters (with recommendations for older individuals as verified by this report) should help increase the trust in public health," she added. "If there is a future pandemic, models such as the one presented herein can help minimize the damage of widely restrictive policies and still allow for protection of those who need it the most."
Federal health officials are moving in that age- and risk-based direction, controversially bypassing the CDC's Advisory Committee on Immunization Practices in making the change. The CDC in May dropped its recommendation that healthy children and pregnant women get routine COVID-19 shots, a move that earned sharp disapproval from some pediatric and infectious disease experts. Earlier that month, FDA officials outlined a plan to limit COVID vaccinations that would allow immunogenicity endpoints for high-risk groups and called for randomized controlled trials for people at lower risk.
"The notion of targeting high-risk groups is in no sense new; pretty much every country targets high-risk groups for vaccination," Paul Offit, MD, of the Children's Hospital of Philadelphia, told MedPage Today. "This paper helps provide even more data that we should focus on those at highest risk. It's not saying 'don't vaccinate children'; it's saying 'don't boost healthy children who don't fit into high-risk groups.'"
Ioannidis and colleagues cautioned that assessing absolute net benefits in younger populations requires "careful consideration of potential additional benefits for nonlethal outcomes and adverse effects" beyond mortality.
"For young people, considerations for vaccination decision-making extend beyond the very rare mortality and may include shorter duration of symptoms and less severe illness," they wrote.
Josh Fessel, MD, former chief medical officer at NIH's National Center for Advancing Translational Sciences, told MedPage Today that the study "is definitely thought-provoking and is an important addition to what should be ongoing data-driven discussions about optimal COVID-19 vaccination practices."
"The study should not be seen as answering any questions that it doesn't directly address, such as what should have been done at any given point during the pandemic based on trying to extrapolate what the effects of the 'should have' situation would have been," he said. "The authors do not attempt to model those kinds of scenarios, and we as readers should not infer them."
For this study, Ioannidis and colleagues used "public literature data" to estimate the number of lives and life-years saved among people vaccinated against COVID from the debut of the first licensed vaccines in December 2020 until October 2024. The researchers compared vaccination strategies globally with a no-vaccinations scenario, based on estimates of infection fatality rate, vaccination effectiveness against death, and the proportion of population who were likely to have been infected pre- and post-vaccination.
Other key study findings revealed that a majority of lives saved (57%) were during the pandemic's Omicron period. The number-needed-to-treat analysis showed that it would take 5,400 vaccine doses to avert one death, and 900 vaccine doses to save one life-year.
Sensitivity analyses revealed a potentially wide range of deaths averted by vaccination, from 1.4 million to 4 million, and 7.4 million to 24 million life-years saved.
While the study authors noted that adverse event risks from vaccination remain contentious, "the number of deaths due to widely recognized and accepted adverse events ... are probably approximately 2 orders of magnitude smaller than the overall benefit."
Study limitations included the study's data sources. For most of the analyzed factors, data mostly came from high-income countries. Data from the two largest countries, China and India, "have major uncertainty on estimates of COVID-19 disease burden, let alone vaccine benefits," the researchers cautioned.
In addition, vaccination effectiveness assumptions were built from multiple vaccines, different doses, varied vaccination policies, and waning effectiveness over time. That complexity can cause "substantial uncertainty and bias," the authors noted. Finally, "life-year calculations are a contentious topic," they conceded.
Disclosures
The study was supported by a gift from Sue and Bob O'Donnell to Stanford University.
Ioannidis and colleagues reported no conflicts of interest.
Gandhi reported no conflicts of interest.
Primary Source
JAMA Health Forum
Source Reference: Ioannidis JPA, et al "Global estimates of lives and life-years saved by COVID-19 vaccination during 2020-2024" JAMA Health Forum 2025; DOI: 10.1001/jamahealthforum.2025.2223.
Secondary Source
JAMA Health Forum
Source Reference: Gandhi M "COVID-19 vaccination saved lives and this matters in 2025" JAMA Health Forum 2025; DOI: 10.1001/jamahealthforum.2025.2237.
https://www.medpagetoday.com/infectiousdisease/covid19vaccine/116674
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