In November, 1789, Dr. Jenner inoculated his eldest child
Edward, aged 18 months, with some swinepox virus, and as
nothing untoward happened, he inoculated him again with
swinepox on April 7, 1791. The child had a slight illness, very
like vaccinia, from which he rapidly recovered. The moment for
the crucial experiment was not yet; it came in due time, but
Jenner had to wait five years for it, and five years are a long
time to a man who is yearning to perform his crucial
experiment. Happily for suffering humanity, in the early summer
of 1796 the opportunity came; the hour and the man were there
together.
