For years, the refrain "safe and effective" has been the cornerstone of public health messaging around COVID-19 vaccines, driving mandates, school closures, and global inoculation campaigns. Yet, a July 2025 Stanford-led study published in JAMA Health Forum delivers a sobering reassessment: vaccines saved an estimated 2.5 million lives globally from 2020 to 2024, a fraction of the 14.4–20 million claimed by earlier World Health Organization (WHO) estimates. With 90% of lives saved among those over 60 and only 2,000 among the under-30s, the study challenges the one-size-fits-all approach to vaccination, exposing flaws in aggressive mandates and raising urgent questions about vaccine efficacy, safety, and public trust. This review dissects the study's findings, and critiques the "safe and effective" narrative.
The Stanford study, led by epidemiologist John P.A. Ioannidis and Italian researchers, estimates that COVID-19 vaccines prevented 2.5 million deaths globally, requiring 5,400 doses per life saved. This is a sharp downgrade from WHO's 14.4 million estimate for 2021 alone, which Ioannidis attributes to "parameters incompatible with current understanding." The study highlights a stark age gradient: 90% of lives saved were among those over 60, with only 299 under 20 and 1,808 aged 20–30. For the under-30s, 100,000 doses were needed per life saved, questioning the cost-benefit ratio for younger populations. Additionally, vaccines saved 14.8 million life-years, mostly among the elderly, with 82% of benefits tied to pre-infection vaccination during the Omicron wave.
These findings challenge the blanket efficacy claims that fuelled mandates. The study's sensitivity analysis suggests a range of 1.4–4 million lives saved, reflecting uncertainty in COVID death tallies, estimated at 7 million globally. Ioannidis criticises "aggressive mandates and messianic messaging," arguing they deterred high-risk elderly from vaccination while fostering hesitancy among the young, where benefits were minimal.
The "safe and effective" mantra, echoed by governments and health agencies, assumed universal vaccine benefits and minimal risks. Yet, the Stanford study reveals a more nuanced reality. While vaccines reduced mortality among the elderly, their impact on younger groups was negligible, 2,000 lives saved among 4 billion under-30s. This raises questions about mandating shots for low-risk populations, especially when 100,000 doses were needed to save one life under 30.
Safety concerns further erode the narrative. A 2024 Washington Times report cited a Global Vaccine Data Network study of 99 million vaccinated individuals, linking mRNA vaccines to myocarditis and cerebral venous sinus thrombosis, prompting restrictions on AstraZeneca's vaccine in some countries. Over 17,500 Britons have applied for vaccine damage payments, with manufacturers adding warnings for myocarditis and pericarditis to mRNA vaccine labels in 2024. Critics like Dr. Meryl Nass, a vaccine sceptic, argue that these risks, particularly for the young, undermine claims of universal safety, especially given the study's low efficacy for those under 30.
The narrative also falters on effectiveness. A 2023 Washington Times editorial noted that 77.5% of Americans contracted COVID despite 81.4% being double-vaccinated, suggesting vaccines failed as infection preventatives, though they mitigated severity. This aligns with the Stanford study's finding that 82% of lives saved were from pre-infection vaccination, implying limited protection post-exposure.
Ioannidis argues that "mandates and punitive measures" reduced vaccine uptake among high-risk elderly while alienating younger populations, producing hesitancy. A 2023 Pew Research Center survey found U.S. trust in government at a historic low of 16%, partly due to inconsistent vaccine messaging. Aggressive policies, like school closures, caused significant harm, learning loss among disadvantaged children, without clear benefits, as children faced minimal COVID risk. Epidemiologist Monica Gandhi, in a JAMA commentary, endorsed the study's call for targeting at-risk adults, criticising blanket mandates.
The push to vaccinate everyone ignored age-stratified risks. The study's 5,400 doses per life saved globally balloons to 100,000 for those under 30, suggesting resources were misallocated. As this is mainstream publication, it seems that the COVID masks are slowly falling.
"A Stanford University-led study estimates that COVID-19 vaccinations saved 2.5 million lives from 2020 to 2024, about 17 million fewer than earlier reports suggested, primarily among older adults.
That's the equivalent of one death averted for every 5,400 vaccine doses administered worldwide during the period, according to the findings published Friday in JAMA Health Forum. Official estimates say 7 million people died from the virus worldwide in those years.
Led by three Stanford researchers, the study noted that 90% of the lives saved were among people 60 or older, and 82% stemmed from vaccinations administered before they tested positive for COVID-19.
Lead author John P. A. Ioannidis, a Stanford epidemiologist, said the estimates are much lower than the 20 million lives that early studies claimed vaccines saved in the first year of inoculations alone.
At the same time, he said they refute the exaggerated estimates of vaccine skeptics who claim the jabs "killed many millions of people."
"I hope that people who have taken or even published extreme positions regarding COVID-19 vaccines, either favorable or unfavorable, will be willing to consider our findings with calm reflection," Dr. Ioannidis said in an email. "We are open to revising our estimates if better data arise in the future."
He said the "substantial uncertainty" that still clings to official COVID death tallies calls for rigorous long-term randomized trials of future vaccines, which did not occur in the rush to inoculate people during the recent pandemic.
According to Dr. Ioannidis, "mandates and punitive measures" aimed at inoculating the young likely kept many older people with major health problems away from the shots, reducing their effectiveness where they were most needed.
"The mandates and the aggressive push to vaccinate everyone probably did not help, and the coercive, almost messianic messaging caused damage to public health with an increase in vaccine hesitancy and loss of trust in medicine and medical science," he added.
Overall, the study estimated that every 900 vaccine doses saved a year of human life, or 14.8 million life-years total. But most occurred among older adults outside of long-term care facilities.
Among the 4 billion people younger than 30 who represent half the global population, the study estimates that vaccines save only about 2,000 lives.
The study found COVID-19 vaccines saved only a quarter of a million people aged 30 to 59, who account for slightly less than 3 billion out of 8 billion people on the planet.
In an invited commentary published alongside the study, epidemiologist Monica Gandhi endorsed its recommendation that future pandemic vaccines focus on reaching at-risk adults rather than the entire population.
"Long-shuttered schools in the U.S. was not necessary to protect children and did harm them in terms of leading to learning loss, especially among children from high poverty backgrounds," said Dr. Gandhi, a University of California at San Francisco medical professor.
Reached for comment, other public health experts not involved in the study offered mixed reactions to it.
"It reinforces and quantifies what we already know about the efficacy of these vaccines," said Dr. Amish Adalja, an infectious disease specialist and senior scholar at the Johns Hopkins Center for Health Security. "The COVID vaccines were essential to ending the pandemic and its onslaught on hospital capacity."
Dr. Meryl Nass, an internist and critic of COVID-19 vaccine mandates who serves as a scientific board member at Children's Health Defense, said the study raises more questions than it answers about the jab.
"Given this finding, which has been repeated in multiple countries, it is difficult to believe that vaccine efficacy saved the lives of millions of people," said Dr. Nass, a skeptic of COVID-19 treatments whose advocacy group was founded by Health and Human Services Secretary Robert F. Kennedy Jr.