John Fewster (1738 – 3 April 1824) was an English surgeon and apothecary in Thornbury, Gloucestershire. He is recognized for his early observation that prior infection with cowpox conferred immunity to smallpox, a discovery that preceded and contributed to Edward Jenner's development of the smallpox vaccine.
Early Life and Education
Fewster was born in 1738, possibly in Stonehouse, Gloucestershire. He was educated at Bristol Grammar School before completing a seven-year apprenticeship at the Bristol Infirmary.
Career and Role in Smallpox Vaccination
In 1768, Fewster observed that two brothers (named Creed) had both been variolated (purposefully infected with smallpox), but one showed no reaction. Upon questioning, this individual had never contracted smallpox but had previously been infected with cowpox. This led Fewster to hypothesize that cowpox infection might protect against smallpox—a notion he had not previously encountered. He is reported to have discussed this possibility at a Convivio-Medical Society dinner at the Ship Inn in Alveston, where the young Edward Jenner, then a medical apprentice, was present.
Fewster followed up on this observation only to a limited extent and did not publish his findings in writing.
In the spring of 1796, Fewster inoculated three children in Thornbury with cowpox, around the same time as Jenner's first vaccination attempts. However, Fewster never made any claim to have discovered vaccination.
Historical Clarifications
Some sources have claimed that in 1765, Fewster read a paper titled "Cow pox and its ability to prevent smallpox" to the Medical Society of London. However, the Medical Society of London was not founded until 1773, making this claim anachronistic. The earliest suggestion that Fewster had written such a paper appeared in 1886, more than a century after the events.
Personal Life
Fewster married Betty Tyson in 1770. He died on 3 April 1824 at approximately age 86 and is buried at St Mary the Virgin Parish Churchyard in Thornbury, Gloucestershire.
