He had gone away for a holiday in 1879 while he was working at fowl-cholera.
Since their earliest and most rudimentary introduction in the late 18th century, vaccines have fundamentally changed the way modern medicine is practiced and have eliminated or managed the incidence of some of the most devastating human diseases. Humankind has benefited from vaccines for more than two centuries, but the path to discovering effective vaccines was long and difficult. The work required a number of brave research pioneers and clinicians.
In this spirit of giving thanks this holiday season, we will explore the history of vaccines and the work of the 19th century pioneer Louis Pasteur, who was the first scientist to create a vaccine in a laboratory setting.
Born in 1822 to humble beginnings in Dole, France, Louis Pasteur was a hard-working, serious child, who at a young age demonstrated a greater interest in the arts than the sciences. Few would have predicted that he would grow up to be one of the most important scientific figures of the 19th century.
During the course of his career, Pasteur made crucial discoveries in chemistry, biology, and medicine. He was the first to discover molecular chirality and spontaneous resolution while studying crystallography. He studied fermentation, demonstrating that it is a chemical process carried out by microscopic organisms. These findings gave him the information necessary to disprove the myth of spontaneous generation and to propose methods for preventing the growth of bacteria in food items. His name quickly became a household word for food safety, e.g. “pasteurization”.
Louis Pasteur in 1857. Source: National Library of Medicine
Pasteur’s studies on microorganisms inspired him to pursue the study of infectious diseases. While studying an epidemic in silkworms that was disrupting France’s silk industry, he isolated the microorganisms causing the disease. This finding led him to propose the germ theory, which simplistically states that many diseases are caused by microorganisms too small to see without magnification. The germ theory would revolutionize the medical world and have a number of important practical consequences, including increased hygiene standards in the medical community and a newfound interest in disease-causing bacteria in the research community.
By the early 1870s, Pasteur had already established himself as a renowned leader in research, and in 1877 Pasteur began to fully immerse himself in the study of disease. At the time, Pasteur was studying chicken cholera (Pasteurella multocida), a diarrhoeal disease that was destroying the breeding chicken population. Influenced by Edward Jenner, Pasteur reasoned that if a vaccine could be found for smallpox, vaccines could be found for all diseases.