How smallpox was eradicated

Smallpox is a contagious disease caused by the variola virus. It is considered to be one of the deadliest diseases to humanity, estimated to have killed more than 300 million people since 1900 alone. On average, 3 out of every 10 people who got infected, died. It is spread by direct and prolonged face-to-face contact between people.

Struggles in treatment and the advent of vaccination.

For hundreds of years, there was no effective treatment for patients that developed smallpox. A controversial treatment would sometimes be used where material from the lesions of infected patients would be delivered into the skin of healthy individuals. While sometimes generating immunity, it would also frequently kill people and/or establish new outbreaks of disease.

Edward Jenner and smallpox virus

This changed in 1796 when Dr. Edward Jenner made an important observation. He noticed that milkmaids who had been exposed to cowpox from the udders of infected cattle were not getting infected with smallpox, so Jenner wanted to test out his theory. He took material from a cowpox sore and exposed James Phipps, a 9-year-old boy, to it. Months after this initial exposure, Jenner exposed James to smallpox and observed that he never got sick. While certainly in conflict with the important modern medical ethics policies we have in place today, his experiment was a resounding success.

Jenner published these findings in 1801 and introduced the world to what we now know as the process of vaccination; by generating an immune response against the related cowpox virus which did not cause disease in humans, protection was given against the more serious smallpox virus.

The goal of world-wide eradication.

The World Health Organization (WHO) started a smallpox eradication campaign from 1966-1980 that primarily relied on mass vaccination of the public. This proved ineffective in areas that were densely populated, so they flipped to preventative measures aimed at stopping the spread of the virus. This included finding and vaccinating anyone who had been in close contact with an infected person. Since smallpox is spread via person-to-person contact, once everyone got vaccinated, the virus could no longer spread and disappeared from circulation. Worldwide eradication of smallpox was declared on May 8, 1980.

This massive accomplishment did not occur without its challenges. Initially the plan was to launch the ‘Global Eradication Campaign’ in 1959, but it suffered from a lack of funds, personnel, commitment from countries and a shortage of vaccine donations from wealthier countries (for example, those in North America and Europe) who kept their vaccine supplies to themselves.

By the time 1966 came around and smallpox was all but a thing of the past in North America and Europe (having been eradicated in 1952 and 1953, respectively), the ‘Intensified Eradication Program’ was able to launch successfully, with a focus on the remaining countries in South America, Asia and Africa. The vaccination campaign was ultimately a success and smallpox is now considered eradicated from the world.

The campaign was helped along by newer technologies such as higher-quality freeze-dried vaccines that could be produced more quickly, the development of the bifurcated needle that made administration easier, and case surveillance systems that allowed for improved tracking of active cases.

Smallpox vaccine

There are currently only 2 places in the world that still have stores of smallpox: The Center for Disease Control and Prevention (CDC) in Atlanta, Georgia and the State Research Center of Virology and Biotechnology (VECTOR) in Koltsovo, Russia. It is important to have some available as a safeguard against the potential for re-emergence or for protection in case of its use as a bioterrorism agent as the majority of our population is now no longer vaccinated.

Vaccination in the modern era.

Vaccine development has allowed us to live longer and reduce our healthcare costs because we are not getting sick as often. We now have valuable vaccines for diseases such as rabies, influenza and many childhood illnesses.

A good example of this is the Measles, Mumps and Rubella (MMR) vaccine that protects children against 3 different diseases, with measles being the most well-known. Since the availability of this vaccine, the number of reported measles cases declined to under 100 people in 2016. Unfortunately, vaccination rates for measles have dropped in recent years and this led to a massive surge in cases, that got as high as 1,282 cases in 2019. The only way we can prevent measles from being re-introduced into society is by maintaining a high rate of vaccination among children.

Another disease that we have almost eliminated from the world thanks to vaccination campaigns is polio. Since 1988, vaccinations against polio have helped reduce the number of active polio cases by 99.9%.

The CDC states that “without our polio eradication efforts, more than 18 million people who are currently healthy would have been paralyzed by the virus.”

Currently polio is only present in 2 countries in the world, Afghanistan and Pakistan. This demonstrates that as vaccination rates increase around the world, disease rates decrease significantly, and people stop getting sick and dying from these very preventable diseases.

Why it matters.

Vaccination is the best tool against disease

The vaccination efforts occurring during the current COVID-19 pandemic are very similar to these other examples in their goal of disease elimination. The more people that get vaccinated, the less illness that occurs and the healthier our population will be. Vaccines are our best tools in preventing the spread of disease and protecting our entire population from its effects.
Technology has advanced significantly over the past couple of centuries; our medical advancements are saving millions of lives a year and vaccines are a big contributor to that. We beat one of the world’s deadliest diseases before, and we can do it again.


Data was informed by:
(1) CDC (2) WHO (3) CDC-Polio