The first vaccine (which did not yet have this name) was administered in 1796 to a child by Edward Jenner, an English doctor, with the aim of protecting against smallpox. Smallpox was known for a long time as a very contagious, incurable and deadly disease, affecting people with high fevers, vomiting and pustules filled with liquid that spread throughout the body. Those who survived had permanent sequelae, such as scars and blindness. It is now known that smallpox existed more than 3 thousand years ago. It is caused by the smallpox virus and has two forms, variola major, more severe, and variola minor, the less severe. The origin of smallpox is not known, but its spread is associated with the expansion of civilizations, trade and population routes over the centuries. The trial of Edward Jenner The hypothesis of protection against smallpox by Edward Jenner was based on: The fact that it was known that milkers infected with cowpox virus were naturally protected against human smallpox . A common practice in many Eastern and African countries – variolation – in which healthy people were exposed to small amounts of material from smallpox skin lesions from sick people, as it was known that if they became infected, they would have a milder disease and mortality was much lower. Variolation had been introduced to Europe about 300 years earlier by Mary Montagu, wife of the English ambassador to Constantinople, who knew it while living in the Ottoman Empire. Thus, Edward Jenner used material collected from cowpox skin lesions from the hands of a milkmaid and administered it to an 8-year-old child. Two months later, he exposed the child several times to material from human smallpox wounds and the child never became ill. The objective was achieved and the name vaccine was born , or vaccinus in Latin, which means derived from vacca (cow). And variolation was progressively replaced by vaccination. The next steps At the beginning of the 19th century, it was already demonstrated that this form of protection against smallpox was effective and throughout this century vaccination against smallpox was practiced in the Western countries, being required, mainly, to travel. However, only later, with the development of vaccine production and conservation techniques, mainly from 1950 onwards, it was possible to develop large-scale actions in an attempt to eradicate this disease, which still killed more than 300 million people in the 20th century. The World Health Organization launched in 1959 the Smallpox Eradication Program and in 1967 the Intensified Smallpox Eradication Program. These programs included several measures, mainly: Universal childhood vaccination programs; Mass vaccination of the population in specific areas; Surveillance and containment of identified cases so that the disease does not spread. The eradication of smallpox Throughout the 19th century, smallpox was controlled and in the 20th century it was eliminated in several regions of the world , first in North America (1952) and Europe (1953) and finally in South America (1971), Asia (1975 ) and Africa (1977). The last two cases of naturally acquired smallpox were recorded in Bangladesh in 1975 (variola major) and in Somalia in 1977 (variola minor). Since then, there have been no new cases of naturally transmitted smallpox. In 1978, the last death from smallpox occurred in England but in this case it was not a natural contagion, but a laboratory accident. On May 8, 1980, the World Health Organization declared smallpox eradicated. In Portugal Smallpox was introduced into Portugal in the 7th century with Arab expansion. In the 15th and 16th centuries, the Portuguese brought the disease to West African countries and Brazil. The first cases described date back to 1423, in Coimbra and Alcáçovas. The last case was registered in 1952, although the disease continued to be diagnosed in the 1960 in the African colonies at the time. In the 20th century, the largest outbreak was recorded in 1918-1919, with 13,202 deaths. It is known that in Portugal variolation was practiced as early as 1768 and vaccination with the vaccine advocated by Jenner in 1799. Despite being mandatory before, in 1965 the smallpox vaccine was included in the National Vaccination Program then created. In 1977, it was no longer administered due to the eradication of the disease. Smallpox is the only human infectious disease that has been eradicated to date through vaccination. A cure for this disease was never discovered before its eradication. The smallpox vaccine was the pioneer , and since then, safe and effective vaccines against many diseases have been developed. And many others are under development. Author: Prof. Saraiva da Cunha Sources: Center for Disease Control. History of Smallpox . David de Morais JA. Surtos epidémicos ocorridos em Portugal na primeira metade do século XX: abordagem histórico-epidemiológica. II – Varíola. Medicina Interna 2012;19:43-50. World Health Organization. History of smallpox vaccine . Meet the Infectious Diseases clinical team at the Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
