John Fewster to save him from smallpox. According to Player Fewster replied that he had already thought of this but had decided against it as, in his view, variolation was very successful and an alternative seemed unnecessary. Nonetheless, Player reports, Fewster went on to inoculate three children in Thornbury with cowpox, during spring 1796. These vaccinations took place at around the same time as Jenner's first vaccination attempts. Fewster never made any claim to have discovered vaccination. John Fewster Dr John Fewster (1738–1824) was a surgeon and apothecary in Thornbury, Gloucestershire. Fewster, a friend and professional colleague of Edward Jenner, played an
Smallpox vaccine lost its potency at ambient temperatures which restricted its use in tropical climates. However, it remained in use into the 1970s where a satisfactory cold chain was available. Animals continued to be widely used by vaccine producers during the smallpox eradication campaign. A WHO survey of 59 producers, some of whom used more than one source of vaccine, found that 39 used calves, 12 used sheep and 6 used water buffalo, whilst only 3 made vaccine in cell culture and 3 in embryonated hens' eggs. English vaccine was occasionally made in sheep during World War I but from 1946 only