Jenner and Smallpox Vaccination in England
Control of Smallpox, Use of Cowpox Lesions for Immunization
May 6, 2009
Smallpox was the first infectious disease to be totally eradicated from the world. That disease has not reappeared since it was declared eradicated by the World Health Organization in 1977.
That amazing eradication and accomplishment has not been duplicated for any other infectious disease. Here is a story of smallpox and vaccination science and dedication that led the world to the eventual eradication of smallpox.
Variolation, Smallpox Immunization, Cowpox and Milkmaids and Edward Jenner
Variolation was the practice of taking small samples of skin lesions of smallpox (see photos below) and scratching some of that matter into the skin of a willing recipent. It was an inoculation and it was termed "variolation". In many cases the variolated person became immune and resistant to smallpox. Unfortunately, sometimes there were bad side effects, like severe disease, or even death, because this was wild, virulent smallpox (Variola major).
Jenner and others knew that dairymaids (milkmaids) became naturally-infected with cowpox, obtained from the udders of cows during hand-milking. Further, these milkmaids were immune to smallpox for, while many English folks came down with smallpox, milkmaids did not succumb to the disease. Edward Jenner, an English physician, used this knowledge of the townsfolk to choose a new alternative to variolation. He called it vaccination since "vaccinus" meant "relating to the cow". ("Vacca" means "cow" in Latin.)
Vaccination Initiated by Jenner in England Spreads Quickly
In 1796 Jenner scratched cowpox into the skin and intentionally infected an 8-year old James Phipps. Amazingly, to prove that the procedure was effective, Jenner inoculated Phipps with smallpox. Phipps was proven to be fully immune. Similar vaccinations were done with other children, and his own son. Jenner published results in 1798 to prove and argue that cowpox vaccination gave immunity to smallpox and that the alternative and dangerous use of smallpox pustules for variolation could be ended. By 1801, just 5 years after the first vaccinations, doctors and others were regularly vaccinating against smallpox and about 100,000 immunizations were recorded in the English population. Within a decade, after the first vaccination, the procedure had spread worldwide.
Vaccine Strains for Smallpox
Smallpox vaccine is produced with a Vaccinia strain, an attenuated virus that is related to smallpox. The exact origin of that strain is unknown.
The vaccine strain can have side effects. Since the vaccine does not contain the Variola smallpox, a person could not acquire true smallpox, but some vaccinees can become ill and rare instances of death attributed to vaccination are known.
Can Smallpox Ever Return?
Although the world has been declared safe from smallpox by a declaration of the WHO, that may not be entirely true. Discomforting to some is the fact that at least two countries, the United States and Russia, retain stocks of virulent strains in frozen and freeze-dried condition. Further, there are poxviruses in monkeys and other primates, that potentially could mutate into forms that could become another smallpox. So far nothing adverse has happened. However, since 1977, when WHO declared smallpox eradicated, all smallpox vaccinations have been discontinued. If the virus were ever to return, billions of susceptible, unimmunized people would exist and make it a devastating epidemic and pandemic. The mortality due to smallpox approached 20-30% during its pandemics. The U.S. retains large stocks of smallpox vaccines for any possible emergencies.
Sources
Magner, L.N., 1992. A History of Medicine. Marcel Dekker, New York. 393pp
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