Although physicians touted vaccination's relative harmlessness compared with the rigors of variolation, it did induce a disease, vaccinia, which could provoke great discomfort and temporary disability. Vaccinations sometimes went terribly wrong, leading to disastrous infections that maimed or even killed. Throughout the nineteenth century, physicians argued about the merits of various vaccination techniques, equipment, vaccine strains, and appropriate aftercare. Vaccination additionally underwent substantial technological change during the course of the century as practitioners shifted from propagating vaccine virus in humans (humanized lymph), to cultivating it solely by transfer in calves and heifers (bovine lymph), and then to treating the lymph with an antiseptic, glycerin (glycerinated lymph).

Medical Knowledge about Vaccination

In 1897, the physician-proprietors of the New England Vaccine Company described the stages of an ideal vaccination in their instructional booklet Variola and Vaccinia. Vaccinators usually scratched or abraded the upper layer of skin on the arm or leg, and then smeared vaccine lymph into these superficial cuts. Three days after the vaccination, a small, firm reddish skin lesion called a “papule” would appear on each scratched site. By the fourth to sixth day it became “a distinct vesicle of a pearly color, with edges a little elevated,” and by the eighth day swelled to its maximum height, “filled with clear lymph, its elevated margin and depressed center being more clearly marked.” As the area around the vesicle swelled and became inflamed, “constitutional symptoms, fever, headache and backache” appeared and could last for several days. Then as the vesicle slowly faded away, it dried up into “a hard, brown scab,” falling off three to four weeks after the initial inoculation to leave “a depressed foveolated scar, having small pits, or apparent pin-holes, in its center.”

Yet the pamphlet also warned that “many deviations from the normal course of the vaccine disease may occur.” Vaccination vesicles did not always replicate perfect textbook descriptions to yield Jenner's classic vesicle that looked like “the section of a pearl upon a rose-leaf.” Edward Cator Seaton, a respected midnineteenth- century British vaccinator, advised that “older children and adults tend to get vesicles that are not perfectly colored or shaped.”