An old, new foe: The global rise in vaccine-preventable diseases

As we emerge from the peak of the COVID-19 pandemic, the term infectious disease has new relevance. In 1800, global life expectancy did not exceed much above 40 years of age.1 Today, global life expectancy around the world nears 73 years of age.1 Part of the reason for the lower life expectancy among our ancestors was the staggering impact of infectious diseases.1 Now, with the discovery and development of vaccinations, life expectancy and quality of life has improved dramatically.

Vaccines have been used for over two centuries to prevent the spread of infectious diseases and have been internationally recognized as cost-effective public health tools.2 Unfortunately, in recent years, a trend in decreasing vaccination coverage has emerged, which is set to threaten decades of global advancement.

A brief history of vaccines

Modern vaccination history began in the late 18th century with the discovery of smallpox immunization by English doctor, Edward Jenner.3 Despite initial controversy, by the beginning of the 19th century, Jenner’s vaccination procedure rapidly spread around the world, and became widely supported by governments and the public alike.4 Over 200 years later, the World Health Organization (WHO) now estimates that the smallpox vaccine has saved more than 10 billion lives since its invention.3

Since those early days, vaccine development has evolved significantly. Researchers have developed new delivery platforms, new adjuvants (an ingredient in a vaccine that enhances the immune system’s response to that vaccine), new approaches in antigen (the part of the pathogen that generates an immune response) presentation, and new stable and efficient antigen production.5

The impact of vaccines

The eradication of smallpox in 1980 is one of the notable success stories of vaccinations. While no other human infectious disease has been truly eradicated in this way, vaccines have undoubtedly been critical in preventing morbidity and mortality.3 To be approved by regulatory bodies, vaccines are required to have a high efficacy rate of 50% or above.6 In this way, they lower the rate of disease transmission across populations, preventing disease, and reducing the severity of symptoms presented by those who become infected.3

In 1974, the WHO launched the Expanded Program on Immunization (EPI) with the aim of universal access to all relevant vaccines.7 This momentum was increased by Gavi, the Vaccine Alliance, which was established in 2000 with the goal of providing vaccines to save lives and protect public health.7 The roll-out of global vaccination programs has since resulted in a significant reduction in the prevalence of several diseases and have rapidly expanded across low- and middle-income countries (LMICs) in the last two decades, significantly reducing morbidity and mortality related to vaccine-preventable diseases.7 So great is the impact of these programs that the WHO estimates that immunization currently prevents 2–3 million deaths every year.7

Aside from the direct benefits to human health, vaccines also benefit the global economy, reducing the impact on healthcare and treatment costs, as well as decreasing the population’s time off work.3 In fact, a US study found that every dollar spent on childhood vaccinations could ultimately save $10 of productivity.8

Emerging threats

Despite vaccinations being considered one of the greatest accomplishments in the history of medicine, in recent years, global vaccination coverage has decreased from 86% in 2019 to 83% in 2020, threatening decades of advancement in this area.5,9 There are several contributing factors to this recent trend, including the antivaccination movement, vaccine hesitancy, resource shortages, and the impact of the COVID-19 pandemic.

While it is undeniable that COVID-19 has disrupted vaccination coverage for other infectious diseases, the world prior to this outbreak was already experiencing a stall in vaccination rates for many diseases.10 In recent years, there have also been reports of outbreaks of vaccine-preventable diseases around the world, including outbreaks of Hemophilus influenzae type b (Hib), varicella, pneumococcal disease, measles, and pertussis (whooping cough) in the US which have been associated with vaccine refusal.11

Vaccine hesitancy, described as the delay in acceptance or refusal of vaccines despite the availability of vaccination services, was also noted by the WHO as one of the top ten threats to global health in 2019.12 This threat continues to grow.

Controversy and misinformation

Vaccines have always been subject to public controversy. The most well-known case was a study published in 1998 by former physician, Andrew Wakefield, in The Lancet that proposed the measles, mumps and rubella (MMR) vaccine resulted in autism in children.13 Although this claim has long since been debunked by the scientific community, this paper has continued to have a lasting impact on public attitudes toward vaccines.

The rise in measles cases is of particular concern as the virus is highly contagious and is continuing to spread around the globe.14 In fact, the WHO estimated that cases increased by 79% in the first two months of 2022 compared with the same time last year.15 In combination with malnutrition and vitamin A deficiency, measles has become particularly deadly in LMICs.16

It is estimated that between 2000–2018, measles immunization saved 23 million lives.17 Unfortunately, the global resurgence of measles cases now threatens to damage the huge advancements made in fighting this virus.

Addressing the threats

The ongoing decline in vaccine coverage requires immediate attention to prevent any further damage to public health. As the world continues to struggle with the effects of the COVID-19 pandemic, it is important to ensure that there is a commitment to building stronger health systems.

For over two centuries, vaccines have been developed and rolled-out to help combat the burden of infectious diseases. Vaccination programs around the globe have saved and improved countless lives, combatting infectious diseases that once caused thousands of deaths annually. But we have not yet won the war. Measles, meningitis, tetanus, and many other infectious diseases are not yet eradicated—but they could be. It is time to say goodbye to these old foes, once and for all.

  1. Shaw‐Taylor L. An introduction to the history of infectious diseases, epidemics and the early phases of the long‐run decline in mortality. The Economic History Review. 2020 Aug;73(3):E1-9.
  2. World Health Organization Regional Office for Europe. Cost effectiveness case studies. 2015. Available at: [Accessed July 2022]
  3. Durán-Méndez A, Jardínez-Vera AC, Jiménez Muñoz E, Peón AN. A brief history of vaccines and an overview of their benefits. Revista de la Sociedad Española de Beneficencia. 2021;2(1-6).
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  5. Kılıç SG, Dolapçı. History of Vaccines and New Vaccine Strategies. Ankara Universites Tip Fakultesi Mecmuasi. Journal of Ankara University Faculty of Medicine. 2021 Apr 1;74(1):1.
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  7. Toor J, Echeverria-Londono S, Li X, Abbas K, Carter ED, Clapham HE, Clark A, de Villiers MJ, Eilertson K, Ferrari M, Gamkrelidze I. Lives saved with vaccination for 10 pathogens across 112 countries in a pre-COVID-19 world. Elife. 2021 Jul 13;10:e67635.
  8. Rémy V, Zöllner Y, Heckmann U. Vaccination: the cornerstone of an efficient healthcare system. Journal of Market Access & Health Policy. 2015 Jan 1;3(1):27041.
  9. World Health Organization. Immunization coverage. 2021. Available at: [Accessed July 2022]
  10. World Health Organization. COVID-19 pandemic leads to major backsliding on childhood vaccinations, new WHO, UNICEF data shows. 2021. Available at: [Accessed July 2022]
  11. Phadke VK, Bednarczyk RA, Salmon DA, Omer SB. Association between vaccine refusal and vaccine-preventable diseases in the United States: a review of measles and pertussis. JAMA. 2016 Mar 15;315(11):1149-58.
  12. World Health Organization. Ten threats to global health in 2019. Available at: [Accessed July 2022]
  13. Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Harvey P, Valentine A. RETRACTED: Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.
  14. UNICEF. Measles cases are spiking globally. Available at: [Accessed July 2022]
  15. World Health Organization. UNICEF and WHO warn of perfect storm of conditions for measles outbreaks, affecting children. 2022. Available at: [Accessed July 2022]
  16. Roberts L. Measles is on the rise and Covid-19 could make it worse. Nature. 2020;580(7804):446-7.
  17. World Health Organization. Measles: fighting a global resurgence. 2019. Available at: [Accessed July 2022]
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