Source / Experimental case publication
Privately published in London in 1798, Edward Jenner's An Inquiry into the Causes and Effects of the Variolæ Vaccinæ argued that cowpox could protect people against smallpox and that protective material could be passed from one person to another.
The book matters not because it records one immaculate “first vaccination,” but because it arranged Gloucestershire testimony, retrospective case histories, deliberate inoculations, smallpox challenges, and coloured images into a claim that practitioners elsewhere could test. Some of its conclusions proved durable; its theory of cowpox's origin and its assurance of lifelong protection did not.
Before the inquiry
Eighteenth-century British writers usually called deliberate infection with smallpox matter “inoculation”; historians often call it variolation to distinguish it from later vaccination. Written accounts place smallpox inoculation in China by the mid-sixteenth century and in parts of the Ottoman Empire and North Africa before its well-publicised adoption in Britain and colonial New England in 1721. Its deeper origin remains uncertain. Jenner's procedure therefore belongs to a long, geographically plural history of immunisation (Boylston 2012).
Variolation could produce immunity, but it deliberately caused smallpox and could be fatal or start further transmission. Jenner used the same technique as a “challenge”: if smallpox matter failed to produce the expected local and general illness after cowpox, he treated that failure as evidence of protection. The method was intelligible to contemporary inoculators even though it exposed subjects to real danger (Jenner 1798; Boylston 2012).
The Inquiry depends on named and unnamed milkers, farm servants, cattle, horses, and recollections reaching back decades. Jenner did not present the familiar later anecdote of a single pretty milkmaid giving him the idea. He wrote that older farmers already knew cowpox, while suggesting that its connection with smallpox may have become visible only once systematic variolation created a test. Occupational experience was evidence, not decorative folklore (Jenner 1798, cases I–XVI and pp. 62–63; Boylston 2013).
In 1774 the Dorset farmer Benjamin Jesty deliberately used cowpox matter on his wife and two sons during a smallpox outbreak. That episode was documented publicly only in 1805, so it cannot serve as a contemporary printed foundation for the 1798 Inquiry; it does show why Jenner should not be called the first person ever to inoculate with cowpox. Jenner's more defensible importance lies in sustained investigation, publication, arm-to-arm propagation, and promotion (Boylston 2013).
From observation to print
14 May 1796: Jenner inserted matter from a cowpox sore on dairy worker Sarah Nelmes into two superficial incisions in the arm of a healthy boy “about eight years old,” subsequently identified as James Phipps. Jenner reported a short illness followed by recovery. The Inquiry names Nelmes in case XVI but leaves the boy in case XVII unnamed, a reminder that later retellings supply information the publication itself withholds (Jenner 1798, cases XVI–XVII; Baxby 1999a).
1 July 1796: Jenner inserted fresh smallpox matter into several punctures and incisions on both of the boy's arms. He reported that no disease followed. This was a single, uncontrolled challenge interpreted through variolation practice; it supported further investigation but could not by itself establish universal or lifelong protection (Jenner 1798, case XVII; Baxby 1999a).
March–April 1797: Two surviving manuscripts show Jenner revising case histories and responding to a reader who pressed him to establish that the subjects had not already had smallpox. These drafts contained only the 1796 deliberate vaccination. Jenner intended a Royal Society audience, but the common story of a formally submitted and formally rejected paper is too certain: no submission appears in the Society's records, and the surviving evidence points to informal consideration by Everard Home and Joseph Banks (Baxby 1985; Baxby 1999b).
March–April 1798: A new local cowpox outbreak allowed Jenner to add a serial experiment. Material taken from a cow was passed through William Summers, William Pead, Hannah Excell, Mary Pead, and J. Barge; other adults and children also received material along the way. Jenner then reported failed smallpox challenges in selected boys. This chain—not the Phipps episode alone—made propagation central to the practical case for vaccination (Jenner 1798, cases XIX–XXIII; Baxby 1999a).
21 June 1798: Jenner dated the dedication at Berkeley and issued the book in London, “printed for the author” by Sampson Low and sold through three booksellers. Private publication made a revised claim available beyond a local or learned-society exchange; it did not mean that its evidence had already won professional agreement (Jenner 1798; Baxby 1985).
How the argument works
The numbered sequence can look more uniform and larger than it is. Fifteen early cases offer mainly retrospective or circumstantial evidence about natural cowpox or related farm exposure followed by later failure to contract smallpox. Case XXI covers “several children and adults,” so even the number deliberately inoculated with cowpox cannot be recovered simply by counting headings (Baxby 1999a; Jenner 1798).
Cases I–XV connect past farm exposure to later variolation or contact with smallpox. Some intervals are long: Joseph Merret's case joins cowpox in 1770 to unsuccessful variolation in 1795. Such histories made duration visible, but they depended on remembered diagnoses, selected survivors, and Jenner's ability to exclude prior smallpox—conditions the reader cannot independently audit (Jenner 1798, cases I–XV; Baxby 1985).
The 1798 chain asked whether fluid from a vaccine lesion could generate another usable lesion without returning to an infected cow. Jenner described five successive human “gradations” from Summers to Barge and reported that the material retained its apparent properties. This was a practical contribution: cowpox was uncommon, while a continuing arm-to-arm chain could carry vaccine across places where no infected cow was available (Jenner 1798, cases XIX–XXIII; Rusnock 2009).
The hand-coloured engravings show lesions on Sarah Nelmes's hand and inoculation sites at different stages. They were meant to help practitioners distinguish useful “true” cowpox from other sores and judge when fluid might be taken. Yet plate 1 is already composite evidence: Jenner states that its early finger lesion came from another person's hand, not Nelmes's. The images are instructional constructions, not an untouched visual record of one case (Jenner 1798, case XVI and plates 1–4; Baxby 1985).
Claims and boundaries
Protection: Jenner's central inference—that an appropriately produced cowpox inoculation could protect against smallpox—proved fruitful and was rapidly tested by others. His stronger language that cowpox left a person “for ever after secure” exceeded his evidence; protection after early vaccination was not invariably lifelong (Jenner 1798; Baxby 1985).
Origin: Jenner argued that “grease,” an inflammatory disease of horses' heels, passed through milkers to cows and then to humans, and he speculated that smallpox itself arose through further transformations. Historians identify that required horse-to-cow sequence as mistaken. His effort to distinguish protective cowpox from visually similar “spurious” bovine eruptions was nevertheless important to a practice that depended on recognising the right lesion (Jenner 1798, opening discussion and conclusion; Baxby 1985).
Terminology: Variolæ vaccinæ in the title means, approximately, “smallpox of the cow.” Jenner used “virus” for infectious material, not for a laboratory-defined viral species, and the noun “vaccination” does not appear in the 1798 text. Readers should not silently equate every sample he described with a later standardised smallpox vaccine (Jenner 1798; Baxby 1985).
Subjects: The experimental series included an infant of six months, several children between about one and eight years old, adults, and paupers previously variolated in the village of Tortworth. The Inquiry records symptoms and useful lesions but not the children's voices, parental authorisation, refusals, or how dependent families understood the procedures. Modern consent rules did not yet exist, but age and social position still shaped whose bodies could become evidence (Jenner 1798, cases XII and XVII–XXIII; Murdoch 2015).
Testing, dispute, and circulation
1798–1799: London physicians George Pearson and William Woodville moved quickly to investigate and distribute cowpox material. At the London Smallpox and Inoculation Hospital, some of Woodville's vaccinated patients developed widespread pustules unlike Jenner's local lesions. Jenner blamed contamination with smallpox; results away from the hospital strengthened that interpretation. The episode made the place of experiment, the identity of the material, and rival claims to authority part of the evidence (Boylston 2013).
Material limits: The book could travel more easily than cowpox. Practitioners needed fresh, effective lymph; they maintained it through arm-to-arm transfer or attempted preservation on threads, glass, and other carriers. Physicians and surgeons mattered, but so did donors, children, parents, philanthropists, ministers, and administrators who kept chains moving. Adoption was therefore an organisational and environmental achievement, not an automatic consequence of reading Jenner (Rusnock 2009; Murdoch 2015).
Unequal mobility: Children became both recipients and living carriers of vaccine material. Later British and imperial campaigns often relied on working-class, orphaned, and colonised children to move lymph between bodies and across distance. That history extends beyond the 1798 book, but the children named and unnamed in Jenner's transfer chain reveal the material practice on which expansion depended (Murdoch 2015).
Reputation: Jenner neither invented immunisation nor first observed that cowpox might protect against smallpox. His achievement was to assemble and publish an experimental programme, demonstrate serial human transfer, refine distinctions in response to criticism and practical failures, and campaign for its use. Separating that documented role from a solitary-discoverer legend makes the Inquiry more, rather than less, historically informative (Boylston 2013; Baxby 1999a).
Using the source
The specified 1798 edition shows how Jenner selected, ordered, named, pictured, and interpreted evidence for readers. Its typography, plates, case divisions, and cautions belong to the argument.
The Inquiry cannot supply a denominator for failed attempts, independent confirmation of remembered illness, complete adverse-event reporting, or the experiences and decisions of its subjects. “Case” is a unit of exposition, not a standard enrolment record.
The fact that practitioners extended vaccination establishes neither Jenner's horse-grease theory nor the adequacy of his 1798 methods. Expansion required later testing, manufacture, transport systems, public programmes, regulation, revaccination, surveillance, and the labour of many communities (Rusnock 2009; Murdoch 2015).
Across the collection
Follow the practitioner, correspondence, experiments, supporters, and disputes surrounding his role in vaccination.
Place the 1796 experiment and 1798 publication on the site's chronological spine.
Trace supply, distribution, mandates, resistance, eradication, and the changing meaning of public consent.
References
London: printed for the author by Sampson Low, 1798. Wellcome Collection catalogue record and complete public-domain digitisation. The primary witness for the title, case sequence, reported procedures, four plates, claims, and terminology. It is Jenner's selected argument, not an independent or complete experimental record.
Vaccine 17, no. 4 (1999): 301–307. DOI: 10.1016/S0264-410X(98)00207-2. Analyses the twenty-three case headings, distinguishes circumstantial histories from deliberate vaccination, and assesses both the slender experimental evidence and the publication's importance.
Medical History 29, no. 2 (1985): 193–199. DOI: 10.1017/S0025727300044008. Peer-reviewed comparison of two 1797 manuscripts with the printed book, documenting revisions, reviewer comments, the addition of the 1798 transfer series, the plates, and Jenner's correct and mistaken theories.
Medical History 43, no. 1 (1999): 108–110. DOI: 10.1017/S0025727300064747. Publishes and contextualises Everard Home's report to Joseph Banks. Baxby finds clear intent to address the Royal Society but no record of formal submission, qualifying the standard rejection story.
Journal of the Royal Society of Medicine 105, no. 7 (2012): 309–313. DOI: 10.1258/jrsm.2012.12k044. Reviews the uneven evidence for inoculation in China, India, the Ottoman Empire, North Africa, Europe, and Britain; useful for locating Jenner after, rather than at the beginning of, smallpox immunisation.
Journal of the Royal Society of Medicine 106, no. 10 (2013): 395–398. DOI: 10.1177/0141076813499293. Reconstructs the practical link between variolation and cowpox testing, discusses Benjamin Jesty's retrospectively documented 1774 inoculations, and follows the Pearson–Woodville disputes after publication.
Bulletin of the History of Medicine 83, no. 1 (2009): 17–36. DOI: 10.1353/bhm.0.0160. Peer-reviewed study of cowpox as a scarce biological material and of the techniques, environments, practitioners, philanthropists, and officials required to move and maintain it.
Journal of Social History 48, no. 3 (2015): 511–535. DOI: 10.1093/jsh/shu112. Examines children as recipients, experimental subjects, and carriers of live lymph, and shows how class, race, empire, and changing ideals of childhood structured anti-smallpox campaigns.