Celebrating the 40th Anniversary of Smallpox Eradication and Learning from its Success

Posted on by Inger Damon, MD, PhD, FIDSA, Director, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases and Rebecca Martin, PhD, Director, Center for Global Health
Dr. Inger Damon
Dr. Rebecca Martin
Dr. Rebecca Martin

This year, 2020, the world is commemorating the 40-year anniversary of the declaration of the eradication of smallpox. Considered to be the greatest achievement in international public health to date, we have many lessons learned from this monumental achievement that today’s public health professionals can apply to current and future disease outbreak efforts across the world. The eradication of smallpox showed us that with political commitment, targeted action, community engagement and quality operations, scientific advancements, continuous evaluation, and global partnerships, the world can eradicate a disease.

A map illustrating the timeline for global smallpox eradication. Share an animated version of this map on social media.
Source: U.S. Centers for Disease Control and Prevention (CDC)

Before it was eradicated, smallpox (caused by variola virus) was a contagious, deadly disease that affected global communities for thousands of years. Smallpox was spread mainly by direct and prolonged face-to-face contact between people through droplets from the nose and mouth when infected individuals coughed or sneezed –– similar to how many other infectious diseases are spread. People with smallpox developed skin sores and rashes, and about 3 of every 10 people with smallpox died.

Many countries attempted over centuries to control the spread of smallpox through various methods, such as variolation, the process of inoculating a person with material taken from the sores of a smallpox patient.  In the late 18th century, several medical practitioners, including Edward Jenner, experimented with inoculating people with cowpox virus to protect against smallpox. Although the precise origin of smallpox vaccine remains obscure, these early efforts using cowpox virus (called vaccinia virus by Jenner) led to broader use of the practice, forming the beginning of what we now know as vaccination.

A Global Program to Make a Difference

Following years of country-based efforts to combat and contain smallpox outbreaks, and after considerable contention, the World Health Organization (WHO) initiated a plan in 1959 to eradicate the disease. Despite many challenges, planners understood the eradication effort would be facilitated by the ease of disease recognition and absence of an animal reservoir. One of the first eradication-related initiatives was to develop methods to standardize the quality of vaccine. By 1967, the program intensified from a mass vaccination program to a targeted, community-focused approach that engaged local volunteers in the community in a collaborative strategy. Two public health pillars of the global eradication campaign became the mainstay of the efforts and still used today: disease surveillance and immunization. However, the campaign faced an uphill battle to successfully create a resourced global partnership with funding, personnel, commitment from countries, and sufficient vaccine supply and special needles needed to deliver the vaccine.  By 1971, smallpox was eradicated from South America, followed by Asia in 1975, and finally Africa in 1977 –– leading to the official declaration of global smallpox eradication in 1980.

South America

Ecuador, 1962: Last known case of variola major on the continent
Brazil, April 19, 1971: Last known case of variola minor on the continent


Somalia, October 12, 1977: Last known case of variola minor in the world


Bangladesh, October 16, 1975: Last known case of variola major in the world

Eradication Lessons Learned for Diseases Now and in the Future

The smallpox eradication program provides a roadmap for today’s public health professionals to guide them in addressing wide-scale public health crises and disease outbreaks. These lessons learned may now be applied to the goals of eradicating wild poliovirus and Guinea Worm. Not only can we learn from the measures taken prior to the eradication of smallpox, but we can also learn much from the ongoing work and research conducted to ensure the world is prepared for disease outbreaks in the future.

Today, public health professionals still employ two key strategies for eradication – immunization and disease surveillance – and regularly evaluate these efforts to strengthen programs addressing complex public health threats. We know that science is always evolving, but these lessons from the success of smallpox eradication should bring us confidence in our ability to improve disease-related global health outcomes, so long as we base our strategies in science and its advancements, engagement of communities, and secure political commitment.

In our disease surveillance efforts, we must be vigilant about timely collecting and reporting of relevant data. Focusing on these key areas will help public health programs be agile in response to potential changes that may occur in the planned response to an outbreak. We must also ensure that our public health campaigns are culturally relevant and engage communities. Global health requires the involvement and participation of people from many different ethnicities, religions, and countries.  To eradicate a disease, all citizens must feel respected and able to participate.

Much like the campaigns to eradicate smallpox, successfully combatting pandemic diseases like COVID-19 and others will require the commitment and collaboration from countries across the world. The vast amount of resources required to fight outbreaks will depend on a global coalition of leaders who are committed to protecting their citizens and the global community. This work goes beyond the science – it’s essential to helping improve people’s lives and bringing the world closer to global health equity and social justice because it will help protect groups that have been marginalized.

Therefore, we must use the lessons learned from smallpox and build on investments in global health security and the global COVID-19 response to respond to emerging threats effectively, including the current COVID-19 pandemic. The sooner we come together around the world to form a united front against infectious diseases, as we did in eradicating smallpox, the sooner we will move toward protecting all citizens of the world.

Posted on by Inger Damon, MD, PhD, FIDSA, Director, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases and Rebecca Martin, PhD, Director, Center for Global HealthTags ,
Page last reviewed: November 20, 2020
Page last updated: November 20, 2020
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