James Phipps, the son of a poor landless labourer, was the first person to be vaccinated by Edward Jenner. On 14 May 1796, Jenner cut into the skin of the 8-year-old boy and infected him with matter from a cowpox sore. Over the following days, James developed a fever, but soon became well again. When Jenner then injected the boy with the more dangerous smallpox, James remained healthy. Two other children who shared a bed with James did not catch smallpox from him either. Encouraged by his success, Jenner went on to test his method on various people over the following two years. All of them were poor - farm labourers and their children, or the inmates of workhouses.

Jenner publicised the case of James Phipps as a success story to promote his new method of vaccination. We do not know if James or his father were paid for the experiment, but later in life Jenner definitely rewarded his first test subject. When James Phipps was married with children, Jenner gave him a free lease on a house. Phipps was grateful to Jenner, and attended the physician's funeral on 3 February 1823. However, if the experiment had gone wrong, Jenner would probably have kept quiet about it, and James Phipps would have been forgotten, like many other victims of medical experimentation.