Vaccines have saved at least 154 million lives over the past 50 years, according to a landmark study published in The Lancet in 2024. That works out to roughly 6 lives every minute of every year since 1974, when the World Health Organization launched its Expanded Programme on Immunization.
Where the 154 Million Figure Comes From
The estimate covers vaccination programs targeting 14 diseases: diphtheria, hepatitis B, measles, polio, tetanus, tuberculosis, pertussis (whooping cough), rotavirus, rubella, yellow fever, Japanese encephalitis, meningitis A, and two bacterial infections that cause pneumonia and meningitis in young children. Researchers modeled what would have happened without these vaccines by comparing actual death rates against projected rates in a world with no immunization programs. The 154 million figure represents deaths averted, meaning people who would have died from these diseases but didn’t because they were vaccinated.
The impact on children has been especially dramatic. Over those 50 years, vaccination directly contributed to a 40% reduction in infant deaths globally. In Africa, where several of these diseases hit hardest, infant deaths dropped by more than 50%.
Measles Vaccination Alone Accounts for Most Lives Saved
Of the 154 million total lives saved, measles vaccination is responsible for 93.7 million of them, about 61% of the entire total. No other single vaccine comes close. Between 2000 and 2023 alone, an estimated 60.3 million measles deaths were averted. Before widespread vaccination, measles killed millions of children annually, and it remains one of the most contagious diseases known. Stopping community spread requires about 95% of a population to be immune, which is why even small drops in vaccination coverage can trigger outbreaks.
Polio: From 350,000 Cases to Under 100
In 1988, wild polio paralyzed roughly 1,000 children every day across 125 countries, with 350,000 cases reported that year. By 2024, confirmed cases of wild polio had fallen to 99, all in just two countries: Afghanistan and Pakistan. The global eradication effort has prevented more than 20 million cases of paralysis. Polio doesn’t always kill, but it permanently disables, so the lives transformed by this vaccine extend well beyond mortality numbers.
Bacterial Vaccines for Children
Two vaccines introduced more recently have already made a substantial difference for young children. Vaccines against Hib (a bacterium that causes meningitis and pneumonia in kids) prevented an estimated 1.2 million child deaths between 2000 and 2015. The pneumococcal vaccine, which targets another common cause of childhood pneumonia and meningitis, prevented about 250,000 child deaths over the same period, with most of that impact coming after 2010 as the vaccine reached more countries.
Smallpox: A Disease Erased Entirely
The 154 million figure doesn’t include smallpox, which was eradicated in 1980 before the study’s modeling period began. Smallpox killed about 3 out of every 10 people who contracted it, and in the 20th century alone it’s estimated to have caused 300 million deaths before vaccination wiped it out completely. It remains the only human disease ever eradicated, and every year without it represents hundreds of thousands of lives that would otherwise be lost.
COVID-19 Vaccines in the First Year
COVID-19 vaccines, developed and deployed at unprecedented speed, saved an estimated 20 million lives in their first year of rollout alone, according to a separate Lancet study. That figure is not included in the 154 million estimate, which focused on the 14 diseases covered by long-standing immunization programs. Adding COVID-19 vaccines to the broader picture pushes the total number of lives saved by vaccination even higher.
The Economic Return
Beyond the human toll, vaccination programs are one of the most cost-effective public health investments that exist. In the United States, every dollar spent on routine childhood immunizations returns approximately $11 in societal savings. Over 30 years of vaccinating U.S. children, the total cost of immunization programs was $268 billion, while the resulting savings reached $2.9 trillion. Those savings come from avoided medical costs, prevented disability, and the economic productivity of people who survived childhood because of their vaccines.