III.—John Phillips, Tradesman.
Had Cowpox when nine years old. Was inoculated with Smallpox by Jenner at the age of 62 without effect.
IV.—Mary Barge, Farm Servant.
In 1767 had Cowpox. In 1791 was inoculated with Smallpox without effect. Had also acted as nurse to Smallpox patients without catching the disease.
V.—Mrs. H——, Gentlewoman.
Had Cowpox when very young, contracted by handling dairy utensils. Was subsequently exposed to Smallpox, “where it was scarcely possible for her to have escaped;” and in 1778 was inoculated with Smallpox by Jenner without effect.
At this point, I would draw attention to the ages of the persons set forth in these Cases: they were past middle life when the susceptibility to Smallpox was either low or extinct. The reason given by Jenner for their production was that he “wished to show that the change produced in the constitution by Cowpox is not affected by time”—a claim which vaccinators at this day surrender, insisting on the necessity of re-vaccination to maintain “the benign influence;” but apart from that consideration, there was nothing extraordinary in resistance to inoculated Smallpox. Without the intervention of Cowpox, inoculators were constantly meeting patients who would not “take,” even with repeated attempts, and especially among elderly people; and some who obstinately resisted inoculated Smallpox, subsequently contracted the disease in the ordinary way. So much Jenner himself allowed, saying—
There are many who from some peculiarity in habit resist the common effects of variolous matter inserted into the skin, and in consequence are haunted through life with the distressing idea of being insecure from subsequent infection. (P. 60.)