But one of the biggest contributors, a new study from the World Health Organization (WHO) concludes, was vaccines.
The paper — authored by a team of researchers led by WHO epidemiologist and vaccine expert Naor Bar-Zeev — estimates that in the 50 years since 1974, vaccines prevented 154 million deaths.
Of that 154 million, 146 million lives saved were among children under 5, including 101 million infants.
The previous decades had seen a spree of important, newly developed vaccines: a joint diphtheria, pertussis, and tetanus vaccine in 1948, a polio vaccine in 1955, a measles vaccine in 1963.
The measles vaccine, in particular, deserves pride of place in this story.
In terms of lives saved, the runners-up — tetanus (28 million saved), pertussis (13.2 million), and tuberculosis (10.9 million) — pale in comparison.
How the researchers tracked the benefit of vaccines Studying the effect of vaccines across all continents, and across a 50-year time frame, is a daunting project.
Any way you slice the data, vaccines saved a ton of lives and prevented a ton of suffering.
In the past fifty years, the world has significantly improved in terms of child safety. Global infant mortality has decreased dramatically since 1974. In that particular year, 10% of newborns passed away before turning one year old. That rate had decreased by more than two thirds by 2021.
This change was fueled by a number of factors, including improved nutrition and reduced poverty, cleaner water and air, and easy access to antibiotics and other medical treatments. However, vaccinations were one of the main factors, according to a recent World Health Organization (WHO) study.
According to the researchers, 40 percent of the decrease in infant mortality can be attributed to vaccines alone. According to estimates in the 50 years since 1974, vaccines have prevented 154 million deaths, according to a team of researchers led by WHO epidemiologist and vaccine expert Naor Bar-Zeev.
146 million of the 154 million lives that were spared belonged to children under the age of five, including 101 million newborns. Vaccines provided their beneficiaries with an astounding 9 billion extra years of life because the prevented deaths were concentrated among young people, who would otherwise live an average of 66 years to life.
Developed in 1974 to build on the agency’s success in eradicating smallpox, the paper was commissioned on the occasion of the 50th anniversary of the WHO’s Expanded Programme on Immunization. It includes a crucial time frame. Important, recently developed vaccines had been developed in a frenzy in the preceding decades, including the measles vaccine in 1963, the polio vaccine in 1955, and the joint vaccine against diphtheria, pertussis, and tetanus in 1948. Even though the diseases these vaccinations prevented caused enormous harm, they were not widely accessible in the Global South as of 1974, despite being swiftly adopted in wealthy nations.
That dramatically changed over the next fifty years thanks to immunization campaigns run by the World Health Organization and then Gavi, a multilateral organization formerly known as the Global Alliance for Vaccines and Immunization. The measles vaccine was administered to 68 percent of one-year-olds in sub-Saharan Africa in 2021; the tuberculosis vaccine was administered to 78 percent, and the vaccines against hepatitis B, polio, and diphtheria/tetanus/pertussis were administered to 70–71 percent of children.
Significant gains resulted from this progress. In this tale, the measles vaccination in particular merits prominent placement. As a result, the researchers come to the conclusion that vaccines have prevented the greatest number of deaths overall—93.07 million deaths avoided from 1974 onward. The next three most common diseases in terms of lives saved are tuberculosis (10.9 million), pertussis (13 point2 million), and tetanus (28 million). Measles was eradicated by vaccination, albeit some of that progress may be reversed by anti-vaccine activists. Measles was once a deadly disease that was widespread and quickly spread, but vaccination helped to eliminate it.
Redoubling efforts to discover and distribute new vaccines for diseases like tuberculosis and malaria could have a similarly transformative effect. The data serves as a reminder that vaccines have historically been one of our best tools for saving lives.
How the researchers monitored the vaccination’s benefit.
It is an enormous undertaking to research the effects of vaccinations over a 50-year period and on every continent. The 21 authors of this paper are not a coincidence. (And let’s offer them the recognition they merit. The following people are listed in that order: Andrew Shattock, Helen Johnson, So Yoon Sim, Austin Carter, Philipp Lambach, Raymond Hutubessy, Kimberly Thompson, Kamran Badizadegan, Brian Lambert, Matthew Ferrari, Mark Jit, Han Fu, Sheetal Silal, Rachel Hounsell, Richard White, Jonathan Mosser, Katy Gaythorpe, Caroline Trotter, Ann Lindstrand, Katherine O’Brien, and Naor Bar-Zeev. ).
In essence, the paper combines three different types of research findings and data:.
Based on the UN World Population Projections dataset through 2021 and its projections for mortality in 2022–2024, the actual infant, child, and overall mortality across countries from 1974 to 2024 are estimated.
vaccination rates by nation and year, derived from the Vaccine Impact Modeling Consortium and WHO databases.
The Global Burden of Disease study’s estimates of the impact of vaccination on tuberculosis, tetanus, pertussis, diphtheria, and other diseases, as well as models of how measles, polio, hepatitis B, and several other diseases spread in the absence of vaccines, are empirically verified.
In other words, they created a version of history where all that vaccination didn’t happen, and they modified actual death rates and health statistics accordingly, based on what is known about how many people have been vaccinated in the last fifty years and how effective vaccines are.
This invariably entails completing certain data gaps. They point out that data on vaccine coverage begins in 1980 rather than 1974 in many countries; in these countries, they contend, vaccination coverage was so low that it is reasonable to assume no vaccination in 1974 and a continuous increase from that point on. They also perform sensitivity analyses, which demonstrate that different approaches to this issue result in headline outcomes that are comparable.
An additional perspective on the benefits of vaccination is made possible by years’ worth of health data. While some illnesses, like polio, are not as deadly as others, like measles, they can still have a lifelong detrimental effect on health that can even result in muscle paralysis. (For example, although many medical professionals now doubt that polio caused Franklin Delano Roosevelt’s paralysis, it certainly could have. ).
Vaccines have prevented and saved a great deal of suffering and death, regardless of how the statistics are interpreted.
