Among the many triumphs of medicine, few stories rival the defeat of smallpox, a disease that was declared officially eradicated in 1980. It was the first virus to be successfully eliminated, alone along with rinderpest in 2011.
In this article, we will explore the path to the defeat of smallpox, highlighting the crucial role of international cooperation and scientific discoveries that revolutionized medical history.
What was smallpox?
Smallpox was an infectious viral disease caused by the Variola virus and characterized by fever, sore throat, and the characteristic rashes, red spots that quickly turned into fluid-filled vesicles. It was mainly transmitted airborne from person to person through respiratory droplets.
There are two forms of smallpox:
- Variola minor, also known as alastrim, which causes a milder form of the disease, with a mortality rate of 1%.
- Variola maior which is characterized by more severe clinical manifestations, presenting a lethality rate of 30% to 35%. Those who survive may face long-term complications, including scarring, blindness resulting from corneal ulcers, and limb deformities caused by episodes of arthritis and osteomyelitis.
From treatment to vaccine
The history of the first smallpox treatments is very ancient and begins in India, around the first millennium B.C. with the technique of variolization. This consisted of the inhalation of pulverized smallpox scabs or material obtained by scratching the skin lesions of mild sufferers. If carried out successfully, this generates immunity to smallpox with the risk, however, for the patient to go on to severe infection. The practice has a lethality rate between 0.5 and 2%, still far better than the disease.
The practice began to spread and be used worldwide until 1796, when British physician Edward Jenner discovered that immunity could also be achieved by inoculating the patient with material from cowpox lesions, rather than human. The procedure proved to be extremely safer than variolization, also posing no risk of disease transmission.
Soon the practice spread rapidly throughout the world and took the name “vaccine,” precisely because the material used came from cows, “vaccae” in Latin.
Following the introduction of the smallpox vaccine there were many campaigns that attempted to eradicate the disease. Each of these had little success. Therefore, in 1967, WHO stepped up its efforts, contributing $2.4 million annually and working in collaboration with other international bodies, national governments and volunteers.
The elements of success were two:
- Large-scale vaccination, especially in developing countries.
- Constant surveillance by which smallpox cases were reported and tracked accurately. This close monitoring enabled outbreaks to be identified quickly and preventative measures to be taken.
After decades of intensive efforts, WHO announced in 1980 that smallpox had been eradicated. It was the first disease to be eliminated through deliberate human action.
This success left a lasting legacy in the history of public health, proving that international cooperation, determination and science can defeat even the most serious diseases.