It was quite a victory, then, when English physician Edward Jenner developed an inoculation against smallpox in 1796. Armed with the knowledge that milkmaids who had been exposed to cowpox ...

This practice became widely accepted but was eventually superseded by Jenner's work based on the hypothesis derived from widespread observation and first formulated in 1798 that cowpox infection ...

Jenner noted that his milkmaids did not get smallpox. He suspected that they were prevented from getting the disease because they had previously contracted cowpox (a disease similar to smallpox ...

A young milkmaid had told him how people who contracted cowpox, a harmless disease easily picked up during contact with cows, never got smallpox, a deadly scourge. With this in mind, Jenner took ...

And this is where Edward Jenner comes in. Jenner noticed that milkmaids who caught cowpox – a disease related to smallpox but far more mild – didn’t catch smallpox. This gave Jenner an idea ...

But the method was dangerous. Jenner began experimenting in his home town, Berkeley, Gloucestershire. Many people there believed that diarymaids who had caught cowpox could not catch smallpox. Cowpox ...

Jenner hypothesised protection was due to contact with cowpox lesions and went on to test his theory on an eight-year-old boy called James Phipps. In 1796 he immunised James with fluid from a ...

Also the difference between the vaccine used by Jenner (cowpox virus) and the twentieth century smallpox vaccines (vaccinia virus, a poxvirus species distinct from cowpox) might have been ...