New study shows millions saved by COVID vaccination

COVID-19 vaccination saved an estimated 2.5 million lives, according to a new modeling study published in JAMA Health Forum (2025;6[7]:e252223).

The greatest benefit was seen in people 60 years of age and older, which accounted for 90% of the 2.5 million people saved. In addition, more than 80% of lives saved were vaccinated before any infection.

“The article by Ioannidis et al shows a substantial benefit of COVID-19 vaccination with a likely 2.5 million lives saved from the rapid development and deployment of the COVID-19 vaccines,” Monica Gandhi, MD, who wrote a corresponding editorial (JAMA Health Forum 2025;6[7]:e252237), told Infectious Disease Special Edition. “In 2025, when the benefit of vaccination seems to be doubted, these data show us definitively how important and life-saving vaccines are for infectious diseases.”

Even though the number is conservative compared with previous literature, it still is aligned with what public health officials know about COVID-19 vaccination, Paul Offit, MD, the director of the Vaccine Education Center and an attending physician in the Division of Infectious Diseases at Children’s Hospital of Philadelphia, told IDSE.

“Their findings were similar to others, which is that there are groups that have a higher and lower risk,” said Dr. Offit, who was not involved with the research.

Vaccination Saves Lives

The 2.5 million lives saved (sensitivity range, 1.4-4.0 million) corresponds with one death averted per 5,400 vaccine doses administered. In addition, an estimated 14.8 million life-years were saved (sensitivity range, 7.4-23.6 million life-years), which corresponds to one life-year saved for every 900 vaccines administered.

These numbers are much more conservative than previous estimates; however, they include a longer duration (the start of vaccination in 2020 to 2024) and are global estimates including all age groups. One highly cited study had found an estimated 14.4 million deaths prevented within the first year of COVID-19 vaccination (Lancet Infect Dis 2022;22[9]:1293-1302). “The outcomes are indeed quite different and substantially more conservative versus the earliest estimates based on 2021 speculations,” lead researcher John Ioannidis, MD, DSc, a professor of medicine and epidemiology and population health at Stanford University, in Palo Alto, Calif., told IDSE. “I am not sure I would call it surprising. In 2021, there was tremendous enthusiasm about vaccines with overestimation of their effectiveness, little appreciation of its substantial waning and less credible estimates about the infection fatality rate of the virus.”

However, Dr. Offit said the findings of Dr. Ioannidis and his colleagues support current understanding. “I don’t think he really said anything we didn’t already know,” Dr. Offit said. “When we had this vaccine come out in December 2020, the goal of this vaccine was to keep people out of the hospital, keep them out of the intensive care unit and keep them out of the morgue.”

And that is what the vaccine has done.

COVID-19 affects four high-risk groups, he said:

1. people who are immunocompromised;
2. adults who are older than 75 years of age;
3. patients with chronic heart or lung disease; and
4. pregnant people.

This study supports that literature—that older people see more benefit from vaccination because they are at higher risk.

Of note, COVID-19 is not over and continues to affect morbidity and mortality in the United States and globally. According to the CDC’s estimates from Oct. 1, 2024, to June 7, 2025, COVID-19 has caused approximately 9.8 million to 16.1 million illnesses, 2.4 million to 3.8 million outpatient visits, 270,000 to 440,000 hospitalizations and 32,000 to 51,000 deaths, according to Adam MacNeil, PhD, MBA, the deputy branch chief of the CDC’s Epidemiology, Respiratory Viruses Branch and acting director of its Coronavirus and Other Respiratory Viruses Division. Dr. MacNeil recently presented these data at the June Advisory Committee on Immunization Practices (ACIP) meeting.

Less Risk for Children

The paper also found that vaccination saved fewer lives for younger people, particularly children and adolescents. But this also is well known, according to Dr. Offit, who is a pediatrician, although it does not equate to no risk for younger age groups. “Everybody is still at some risk. There’s nobody who is at zero risk,” he said. “But it’s certainly true that those healthy young children were at a much lesser risk than, say, someone who was over 75. That was clear.”

The question, Dr. Offit said, is whether those at less risk should be required to receive booster shots—not whether they should receive the primary COVID-19 vaccination series. “Most countries in this world don’t give a yearly vaccine to otherwise healthy people, meaning to people who don’t fall into those four high-risk groups,” he said.

Dr. Gandhi also said this research could help answer that question. “This kind of analysis may lead us to adopt more nuanced approaches to vaccination strategies, especially when it comes to booster vaccines, like recommending them for those most at risk for an infection,” said Dr. Gandhi, who is the director of the UCSF-Bay Area Center for AIDS Research; a professor of medicine and the associate chief of the Division of HIV, Infectious Disease and Global Medicine at the University of California, San Francisco; and the medical director of the “Ward 86” HIV Clinic at Zuckerberg San Francisco General Hospital.

In April 2025, the former ACIP board took up this question, but the board has been replaced, and although the new committee reviewed the COVID-19 data, they did not discuss vaccination. Robert F. Kennedy Jr., the secretary of the Department of Health and Human Services, announced no primary vaccinations are recommended in healthy children and pregnant people.

However, pregnancy is one of the four conditions that put people at risk. And this is not aligned with recent data showing that children, although at much lower risk than older adults, can still experience severe outcomes from COVID-19, particularly in very young children. Although hospitalizations continue to be higher among those 75 and older, followed by adults 65 to 74, infants 0 to 6 months old were the third most likely age group to be hospitalized from COVID-19, according to Dr. MacNeil. Since they are not recommended to receive COVID-19 vaccination, vaccinating during pregnancy can afford them some protection, according to the CDC.

“The rates of hospitalizations among infants less than 6 months are nearly identical to those aged 65 to 74, with cumulative rates of 268 and 266 per 100,000, respectively. Similarly, rates among children age 6 months to 23 months are nearly equal to those among adults ages 50 to 64 years,” Dr. MacNeil said.

The sources reported no relevant financial disclosures.

By Meaghan Lee Callaghan