Vaccine Update: Global Vaccine Efforts Result in Significant Impact Over the Last Fifty Years

Column Author: Christine A. Symes, MSN, APRN, CPNP       

Column Editor: Angela Myers, MD, MPH | Pediatric Infectious Diseases; Division Director, Infectious Diseases; Medical Director, Center for Wellbeing; Professor of Pediatrics, University of Missouri-Kansas City School of Medicine; Clinical Assistant Professor of Pediatrics, University of Kansas School of Medicine

A new study by the World Health Organization (WHO) demonstrates that an estimated 154 million lives have been saved by global vaccination efforts over the past 50 years through the Expanded Programme on Immunization (EPI), now named the Essential Programme on Immunization. The 50-year anniversary of this program was felt to be an important timepoint to assess the impact of the program, so a modeling study was completed to estimate the global and regional public health impact of vaccines provided by the EPI. The EPI was founded in 1974 by the World Health Assembly with a goal of vaccinating all children against diphtheria, measles, pertussis, polio, tetanus, tuberculosis and smallpox. Currently, the EPI aims for universal immunization against 13 diseases and, in certain situations or regions, an additional 17 diseases. The program aims to reach infants, children, adolescents and adults. When the EPI was founded, fewer than 5% of the world’s infants had access to routine vaccination. Currently, 84% of infants across the globe are vaccinated, with three doses of diphtheria, tetanus and pertussis vaccine used as a marker for immunization coverage. Of the 154 million lives saved, an estimated 101 million are children from birth to 1 year of age, and 95% of total lives saved are of children under the age of 5 years. The study, published in The Lancet, reveals that immunizations have the largest impact of any health initiative ever.¹ The measles vaccine leads with the biggest impact in reducing infant mortality and is estimated to account for 60% of the lives saved, or 94 million lives. Vaccines against 14 diseases (diphtheria, Haemophilus influenzae type B, hepatitis B, Japanese encephalitis, measles, meningitis A, pertussis, invasive pneumococcal disease, polio, rotavirus, rubella, tetanus, tuberculosis and yellow fever) account for a reduction in infant mortality by 40% globally and 50% on the African continent.

The study highlights successes, such as the eradication of smallpox and the near eradication of polio. For polio alone, it is estimated that 20 million people were spared from being paralyzed. For each life saved due to vaccinations, it is estimated that each individual gained 66 years of healthy living for a total of 10.2 billion years of full health over the last 50 years. However, there is still work to do, as 67 million children globally are missing one or more vaccines since the onset of the COVID-19 pandemic. Measles is a case in point, with 33 million children missing a dose of vaccine in 2022. Population coverage of 95% or greater is needed to protect from outbreaks. The global rate of coverage from the first dose of vaccine is currently 83%, and with both doses it is 74%. Work still to be done is evident in the recent rise in measles cases in the U.S. and across the globe.

Vaccines continue to evolve, and newer vaccines against diseases like malaria, cancers linked to HPV, and COVID-19 are now included in global vaccine initiatives. New collaborations have also formed to increase the impact of the EPI. In 2000, the WHO, UNICEF and the Bill and Melinda Gates Foundation teamed up as partners to form Gavi, the Vaccine Alliance. This alliance aims to assist the poorest countries to increase vaccine coverage and ensure access to new vaccines that can expand protection against vaccine-preventable illnesses. Gavi now provides 20 vaccines and gives credit for its success to EPI, building on the partnerships and progress made over the past 50 years.

Immunizations given through the EPI have provided the primary benefit of reduction in infectious diseases through vaccination efforts, but there have also been secondary benefits. Immunizations have also provided the opportunity for other life-saving interventions such as bed net distribution for the prevention of malaria, maternal tetanus prevention, and nutritional screening and support. The additional lives saved due to these efforts were not included in this study, but the 154 million lives saved is thought to be a conservative number, if secondary benefits are also considered. In reflection on the first 50 years of the EPI program, the study concludes: “The large and ubiquitous gains that can be achieved have, through concerted collaborative effort, been achieved. The next 50 years … will require improvements in targeting and reach, especially for measles vaccines, amid future complex realities for unvaccinated and under-vaccinated children and communities.”¹ This is a time to reflect on the past 50 years and celebrate the successes and lives saved through vaccination programs, but it is also a time to recommit to local and global vaccination efforts to continue to protect children and communities from vaccine-preventable morbidity and mortality.

Reference:

1. Shattock AJ, Johnson HC, Sim SY, et al. Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization. Lancet. Published online May 2024. doi:10.1016/s0140-6736(24)00850-x