An Inquiry into the Causes and Effects of the Variolae Vaccinae

Edward Jenner publishes his Inquiry on cowpox vaccination

The book that helped launch vaccination ran to 75 pages and was privately printed at its author's own expense.

1798: privately published in London

In 1798 Edward Jenner privately published in London An Inquiry into the Causes and Effects of the Variolæ Vaccinæ: A Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cow Pox — usually shortened to the Inquiry. It presented observations and experiments offered to support the proposition that cowpox protected people from smallpox, and ran to 75 pages plus preliminaries and four leaves of colour plates, printed for the author by Sampson Low.

The exact release date is less certain than the year: a scholarly Medical History article dates its appearance for sale to 17 September 1798, while the dedication is dated 21 June and is sometimes mistaken for publication.

What the Inquiry reported

The book described Jenner's 1796 experiment, in which matter from a cowpox sore on the dairymaid Sarah Nelmes's hand was inserted through two superficial incisions into an approximately eight-year-old boy, James Phipps. Phipps became mildly unwell, recovered, and resisted inoculation with fresh smallpox matter on 1 July 1796 and again months later.

It also described arm-to-arm transmission through five successive recipients, reporting that the protective property persisted through that chain.

Reading the case list carefully

The Inquiry's numbered 'cases' are not 23 successful vaccinations: they include naturally acquired infections, recollections and experimental inoculations of differing evidentiary value. Jenner's own eleven-month-old son appears in the book, but that inoculation did not take.

Publication made the accumulated case histories and the experimental claim available for scrutiny and replication; acceptance was not instantaneous, but independent experimentation and wider circulation followed.

Sources

Researched 23 Aug 2026 6 sources 3 audit passes Date disputed

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

Date disputed. Sources disagree; the research places it at 1798-09-17.

What the sources leave uncertain

The publication year and place are secure, but the exact release date is less certain. A scholarly Medical History article, citing Fisher, dates its appearance for sale to 17 September 1798; the dedication is dated 21 June and is sometimes mistaken for the publication date. Library catalogues generally give only 1798.
Jenner’s numbered 'cases' are not equivalent to 23 successful vaccinations. They include naturally acquired infections, recollections and experimental inoculations of differing evidentiary value.
Modern virology distinguishes variola, cowpox and vaccinia viruses more precisely than Jenner could; statements about the biological identity of his material should retain historical caution.