ANATOMY

Detailed explanation-1: -To test his theory, Dr. Jenner took material from a cowpox sore on milkmaid Sarah Nelmes’ hand and inoculated it into the arm of James Phipps, the 9-year-old son of Jenner’s gardener. Months later, Jenner exposed Phipps several times to variola virus, but Phipps never developed smallpox.

Detailed explanation-2: -The first vaccination He diagnosed cowpox rather than smallpox and Sarah confirmed that one of her cows, a Gloucester cow called Blossom, had recently had cowpox. Edward Jenner realised that this was his opportunity to test the protective properties of cowpox by giving it to someone who had not yet suffered smallpox.

Detailed explanation-3: -Inorder to test his theory, Jenner injected a small dose of cowpox virus into a boy. Once he recovered, Jenner injected the boy with smallpox virus. He observed that the boy did not get the disease. This finding led to the discovery of the smallpox vaccine.

Detailed explanation-4: -After inoculation, vaccination using the cowpox virus became the primary defense against smallpox. After infection by the cowpox virus, the body (usually) gains the ability to recognize the similar smallpox virus from its antigens and is able to fight the smallpox disease much more efficiently.

Detailed explanation-5: -The smallpox vaccine, introduced by Edward Jenner in 1796, was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.