Smallpox Vaccine - Early Vaccination

Early Vaccination

In the early empirical days of vaccination, prior to Pasteur's work on establishing a germ theory and Lister's on antisepsis and asepsis there was considerable cross-infection. One of the early vaccinators is thought to have contaminated the cowpox matter—the vaccine—with smallpox matter (he worked in a smallpox hospital) and this produced essentially variolation. Other vaccine material was not reliably derived from Cowpox, but from other skin eruptions of cows. In modern times an effective scientific model and controlled production were important in reducing these causes of apparent failure or iatrogenic illness.

During the earlier days of empirical experimentation in 1758, American Jonathan Edwards died from a smallpox inoculation. Some of the earliest statistical and epidemiological studies were performed by James Jurin in 1727 and Daniel Bernoulli in 1766. Another early account was Dr John Fewster's 1765 paper in the London Medical Society, entitled "Cow pox and its ability to prevent smallpox". He reported that variolation induced no reaction in persons who had had cowpox. Fewster was a contemporary and friend of Jenner. Dr. Rolph, another Gloucestershire physician, stated that all experienced physicians of the time were aware of this.

At the age of thirteen, Jenner was apprenticed to Dr. Ludlow in Sodbury. He observed that people who caught cowpox while working with cows were known not to catch smallpox. He assumed a causal connection. The idea was not taken up by Dr. Ludlow at that time. After Jenner returned from medical school in London, a smallpox epidemic struck his home town of Berkeley, England. He advised the local cow workers to be inoculated. The farmers told him that cowpox prevented smallpox. This confirmed his childhood suspicion, and he studied cowpox further, presenting a paper on it to his local medical society.

Perhaps there was already an informal public understanding of some connection between disease resistance and working with cows. The "beautiful milkmaid” seems to have been a frequent image in the art and literature of this period. But we know for a fact: In the years following 1770 there were at least six people in England and Germany (Sevel, Jensen, Jesty 1774, Rendall, Plett 1791), who tested successfully the possibility of using the cowpox vaccine as an immunization for smallpox in humans. In 1796 Sarah Nelmes, a local milkmaid, contracted cowpox and went to Jenner for treatment. Jenner took the opportunity to test his theory. He inoculated James Phipps, the eight-year-old son of his gardener, not with smallpox but with cowpox. After an extremely weak bout of cowpox, James recovered. Jenner then tried to infect James with smallpox but nothing happened—the boy was immune to smallpox.

Jenner reported his observations to the Royal Society. Further work was suggested, and Jenner published a series of 23 cases, including his son Edward, where none suffered severely from smallpox. Two years later a society to oppose vaccination had been established in Boston, Massachusetts — an indication of rapid spread and deep interest. By 1800 Jenner’s work had been published in all of the major European languages. The process was performed all over Europe and the United States. The death rate was close to zero with the process, which became known as vaccination and was continued to around 1974 in the UK. Thanks to the development of the smallpox vaccine, the disease was officially eradicated in 1979.

The Balmis Expedition (1803) carried the vaccine to Spanish America, the Philippines and China under commission of the Spanish Crown.

Some years before Dr. Jenner, Benjamin Jesty, a farmer at Yetminster in Dorset (he later moved to and is buried at Worth Matravers) is recorded as observing the two milkmaids living with his family to have been immune to smallpox and then inoculating his family with cowpox to protect them from smallpox. This was done in 1774 and can be found with Crookshank's History and Pathology of Vaccination, London 1889, vol. 1, p. 110ff. But the question of who first initiated smallpox inoculation/vaccination can not be answered properly, as there is in the sources the exact date and time only for the predecessor Plett (1791), but not for Sevel, Jensen and Rendall. Louis T. Wright, an African-American and Harvard medical school graduate (1915), introduced intradermal vaccination for smallpox for the soldiers while serving in the Army during World War I.

Leslie Collier developed a freeze-drying method to produce a more heat stable smallpox vaccine in the late 1940s. Collier added a key component, peptone, a soluble protein, to the process. This protected the virus, enabling the production of a heat-stable vaccine in powdered form. Previously, smallpox vaccines would become ineffective after 1–2 days at ambient temperature.

The development of his vaccine production method played a large role in enabling the World Health Organization to initiate its global smallpox eradication campaign in 1967.