37 June 2020 / www.theengineer.co.uk
at least fi ve simultaneous investigations
were underway in Europe and Britain
testing cowpox vaccination on humans
against smallpox. In Britain, during the
1774 smallpox epidemic, Dorset farmer
Benjamin Jesty successfully vaccinated
his wife and two children with cowpox,
and it is thought that Jenner may have
been aware of Jesty’s work. Where
Jenner comes into the story is that
he managed to tie up some of the
unknowns in his own research.
It had long been common knowledge
that milkmaids were somehow immune
to smallpox due to their routine
proximity to cows and cowpox. Jenner’s
hypothesis was that the well-known
folklore of milkmaid immunity stemmed
from the pus in the blisters they received
from the less dangerous cowpox. To test
this, on 14th May 1796, Jenner inoculated
James Phipps, the eight-year-old son of
his gardener. Jenner got pus samples
from cowpox blisters on the hands of
milkmaid Sarah Nelmes who had caught
the disease from a cow called Blossom.
Phipps presented with fever, but no fullblown
cowpox infection, and so Jenner
went to the next step of challenging
the boy’s supposed immunity with the
variolous material (ie smallpox itself)
that had to date been the standard basis
of inoculation. As no disease followed,
was followed in annual succession by three further papers
developing his ideas on vaccination. But it was to be a long and
diffi cult road to having the concept of vaccination accepted
as an alternative to variolation as the standard for smallpox
prevention, with the medical establishment dithering for
decades over the idea. Eventually, some 17 years after Jenner’s
death, the British government banned variolation and provided
optional vaccination using cowpox free of charge under the
Vaccination Act 1840. It would be a further 12 years before
vaccination became compulsory. Despite not living to see the
full eff ects of his work, Jenner knew enough of his success to
refl ect that, “the joy I felt as the prospect before me of being
the instrument destined to take away from the world one of
its greatest calamities was so excessive that I found myself in a
kind of reverie.”
Although Jenner might have cashed in on his success,
having been widely honoured for his pioneering role in the
emerging fi eld of immunology, his single-minded focus on
his work on the understanding of vaccination and vaccines
meant that his country medical practice fell into neglect and
suff ered fi nancially. To ensure his research into vaccination
could continue, in 1802 Jenner’s colleagues, with the support
of King George III, petitioned the British government for
a grant of £10,000 (approximately £1m today), which was
followed fi ve years later by a further £20,000 after the Royal
college of Physicians had confi rmed the widespread effi cacy
of vaccination. In 1803 he became president of the Jennerian
Society established to promote vaccination to eradicate
smallpox, and in 1805 he became a founding member of the
Medical and Chirurgical Society, that was to become the Royal
Society of Medicine. By 1821 such was his infl uence that he
became physician to the new king George IV and mayor of his
hometown of Berkley, where he is buried having died of stroke
in 1823.
Although the disease may have been eradicated, there
remain two offi cial samples of the virus known to cause
smallpox kept in tightly controlled WHO-sanctioned
government laboratories in the United States and Russia.
Their existence periodically raises the ethical debate over
whether they should be destroyed, with the current position
of both countries being outlined by the former Secretary of
the U.S. Department of Health and Human Services, Kathleen
Sebelius, who says that the dangers of destroying the samples
outweigh the ‘minuscule risk’ a ached to keeping them. Their
destruction, she says, would be purely symbolic and could
leave the world vulnerable should we ever need to conduct
further scientifi c research into the virus.
Jenner’s legacy is best articulated in the opening
sentences of a resolution by the World Health Assembly
published on 8th May 1980 that “declares solemnly that the
world and its peoples have won freedom from smallpox,
which was a most devastating disease sweeping in epidemic
form through many countries since earliest time, leaving
death, blindness and disfi gurement in its wake…”
I hope that some
day the practice of
producing cowpox in
human beings will
spread over the world.
When that day comes,
there will be no more
smallpox.
Edward Jenner (1749-1823)
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Phipps’s immunity to smallpox was
challenged repeatedly. The signifi cance
of these procedures is that they made
signifi cant inroads into proving not just
that cowpox could provide immunity to
smallpox, but that the protective cowpox
pus could be eff ectively inoculated from
person to person and not just directly
from ca le. Jenner coined the term
‘vaccination’ that linguistically has its
roots in the Latin adjective vaccinus,
meaning ‘of, or related to, cows.’
Jenner pressed on with his research
and in 1798 published a monograph
entitled An Inquiry into the Causes and
Eff ects of the Variolæ Vaccinnæ, which
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