Edward Jenner's unpublished cowpox inquiry and the Royal Society: Everard Home's report to Sir Joseph Banks.

Edward Jenner's Inquiry into the causes and effects of the variolae vaccinae ... known by the name of the cow pox, published in 1798, contains the evidence on which he based his claim that inoculated cowpox (later called vaccination) induced lifelong immunity to smallpox. He did one vaccination in 1796, but more important was the small series of vaccinations done in 1798 which showed that vaccine maintained its effectiveness through at least four serial arm-to-arm transfers.1 Those interested in Jenner and vaccination will know that he originally intended to publish his evidence in the Philosophical Transactions of the Royal Society; also that two different manuscripts of the Inquiry survive. Both have been compared with the published version; the manuscripts were written during March and April 1797 and so describe only the first vaccination done in 1796.2 That Jenner intended to submit his work to the Royal Society is evident from the phraseology used in the manuscripts, and is confirmed in a letter written by him probably in 1809.3 However, other manuscript versions existed and there is no reason to assume that either of the surviving manuscripts was the one actually