In 1880, a Parisian veterinarian sent Louis Pasteur samples from two dogs that had died of rabies. The number of rabid dogs had increased in Paris, and veterinarians had become concerned about the problem. Pasteur then began careful work on rabies, attempting to infect other animals with rabies and identify the site and cause of infection. Pasteur would continue to work with rabies over the next several years. In 1884, having tried to attenuate the rabies virus in monkeys, Pasteur turned to a different method to produce the vaccine. Pasteur predicted that drying of the infected tissue might weaken the virus. Pasteur was able to use a series of less-attenuated vaccines over several days to prevent rabies in dogs that had been infected. The work was dangerous: he and his assistants often had to handle the rabid animals and take samples from them. Pasteur announced to the French Academy of Sciences that he had successfully protected dogs from fatal rabies by use of his attenuated rabies vaccine.
On 6th July 1885, nine-year-old Joseph Meister was brought to Pasteur who was severely bitten by a rabid dog. Several factors made Pasteur’s potential involvement in the boy’s care controversial. Pasteur had never before successfully used the vaccine on a human. The concept of attenuation of viruses and bacteria was in its infancy at this time. Injecting a human with a disease agent, even a weakened one, was a new and controversial action. Pasteur was not a medical doctor and might have faced serious consequences had Meister not survived the injections. Pasteur felt certain that the boy would die from rabies infection if he did nothing. So he began the course of 13 injections, one each day, of vaccine made from rabbit nervous system tissue. Each successive injection contained a less-attenuated (stronger) virus.
Meister never developed rabies, and the incident was regarded as a success. Later in life, Meister worked as caretaker of Pasteur’s tomb at the Institut Pasteur in Paris.
Louis Pasteur received a commission from a maker of beet root alcohol in 1856 while working at the University of Lille. The owner had grown tired of seeing entire batches of his product poured out before they could be sold. Pasteur dove into the research, carefully examining beet root juice at each stage of fermentation. As he observed the shift, he noticed a number of spherical organisms floating in the liquid — yeast, the microbe that consumes sugar to transform it into alcohol. Days later, as the juice soured and became unusable, Pasteur looked again and found something quite different: rod-shaped organisms — a bacteria. He came to the conclusion “germs” caused the change, a far-reaching discovery with implications in medicine.
With his research proved, Pasteur received an appointment from Emperor Napoleon III to apply his knowledge to French wine. Working in conjunction with his research assistant Bernard beginning on April 20, 1862, Pasteur came up with exact measurements for temperature and the amount of time necessary for preservation. The results were a revelation: wine could last much longer so long as it was not contaminated after being pasteurized. Within months, beer and vinegar were added to the list of materials subject to the process, literally saving vast portions of French agricultural products for export. Years later, Pasteur’s method would be turned to milk.
If there’s one food science breakthrough that stands apart from the rest, it’s pasteurization, milk pasteurization to be specific. Its very adoption changed the health of world. During the 1850s, fewer than half of all children born lived to see their 5th birthday, with tainted milk being the biggest cause of illness. Through separate approaches of low- and high-heat, pasteurization eliminated tuberculosis bacteria and drastically reduced the number of infections suffered during the early 20th century. Because of Pasteur and Bernard’s work, tens of thousands of life-threatening illnesses are avoided every year.