In this video we’ll be exploring the impact of one of the most significant epidemic diseases
to shape world history, and that is smallpox.
In the words of medical historian, Roy Porter, epidemics arose with society and sickness
has been and will remain a social product no less than the medicine which opposes it;
civilization brings not just discontents, but diseases.
Paleolithic society, or society prior to the advent of farming, saw very few epidemic diseases.
People lived in small groups and practiced nomadic lifestyles in which they weren’t
in one place long enough to pollute the environment.
They had no domesticated animals, which are themselves sources of epidemic diseases, and
they ate a relatively healthy diet.
But the advent of farming, the Neolithic Revolution, changed all of that.
As farming brought civilization, and brought with it permanent settlements, large social
groups, close contact with animals, and monoculture diets, humans came into contact with new pathogens.
Some of those pathogens – like influenza or tuberculosis – came from animals.
Others – like cholera or typhoid – came from a contaminated water supply.
And still others – like malaria – came from insect and vermin that infested human
civilizations and these pathogens and the diseases they brought with them often affected
human civilizations that were nutritionally deficient – whether because of food shortages
or because of reliance on monoculture had resulted in vitamin or nutrient deficiencies.
So the pathogens that brought epidemic diseases brought destruction into human societies,
and we’ve named a few, but there are hundreds of others – measles; polio; hepatitis; diphtheria;
whooping cough; the list goes on and on.
But what we want to do today is to take a look at one of the deadliest and most destructive
epidemic diseases in human history – smallpox.
The primary form of smallpox, that has affected human civilizations, is caused by the variola
virus; its symptoms begin with flu-like symptoms and then those flu-like symptoms give way
to a rash across the body; the rash results in skin sores that fill with a thick, opaque
liquid that eventually form pustules; the pustules form a crust and scab over, and then
within a few days those scabs fall off – typically leaving scars.
Smallpox, throughout history, has been highly lethal and highly contagious – killing about
thirty percent of the people it infected and leaving others scarred, sterile, or if the
pox virus infected the eyes – blinded by the effects of smallpox.
Less common strains, like hemorrhagic smallpox, had a fatality rate much closer to a hundred
percent.
So it was an incredibly deadly and destructive virus.
Smallpox was eradicated from the world in 1979, making it the first epidemic disease
completely eradicated in world history.
But before that, smallpox was responsible for billions of deaths – estimates rest
at about three hundred to five hundred million in just the 20th century, and smallpox dates
much further back than that.
So smallpox and the destruction wrought by smallpox has defined human history in many
ways.
It’s believed that the disease originated about ten thousand years ago in Africa, particularly
in eastern Africa, and then spread throughout the ancient world.
A 2015 article from The Journal of Viruses suggests that the variola virus emerged in
east Africa as a mutation of a closely-related virus that evolved as the domesticated camel
emerged, as a new host.
This virus developed into repeated epidemics within a few millennia, and ravaged human
civilizations, human populations, across the globe.
There’s evidence of Egyptian mummies bearing the scars of pox, descriptions of what appear
to be smallpox appear in medical treatises.
There are mentions in Chinese and Indian literature.
The mortality rate in these ancient civilizations, and in future generations, was exceptionally
high so many societies developed the custom of not naming infants until after they’d
survived the pox virus.
So smallpox spread from Africa into Asia, and then from Asia into Europe; smallpox appeared
in large parts of Europe by the Middle Ages, and there are contemporary accounts of the
disease decimating populations across Europe.
So the spread of smallpox is closely connected to the movement of people across regions and
continents in world history, and that would continue into the early modern period as well,
as the Europeans spread smallpox into the Americas, where the devastation was even greater.
In the so-called Old World – Europe; Asia; and Africa – the most common form of smallpox
killed perhaps thirty percent of its victims, while blinding and disfiguring many others.
But the effects were even worse in the Americas, where the indigenous populations had little
to no immunity to the disease.
They’d had no exposure to smallpox prior to the arrival of the Europeans at the end
of the 15th century, and therefore had developed no resistance to the disease, and so smallpox
ripped through Native American populations, devastating the Inca; devastating the Aztecs.
Historians believe that smallpox and other European diseases reduced the indigenous populations
of North and South America by as much as ninety percent, making it a blow far greater than
any military defeat or any advantage from military weaponry.
So it’s fair to say, as historian Jared Diamond has, that disease was – if not THE
decisive factor, at the very least a crucial determinate in Europeans’ dominance in the
modern era.
The ability of smallpox to weaken the native populations opened them up to easy conquest
by the European colonists, and allowed Europe to establish dominance over the Americas – and
that dominance and use of smallpox as a weapon would continue.
In fact, there are suggestions that Lord Jeffery Amherst – commander-in-chief of the British
forces in North America during the Seven Years War, also known as the French and Indian War,
in North America – even advocated handing out smallpox infected blankets to his Native
American foes in 1763.
So smallpox was not only at the center of migrating populations, and at the center of
connections between civilizations, but was defined and used by conflict by civilizations.
It would shape the nature of history, not only in the ancient and medieval worlds, but
in the early modern and modern worlds as well.
Fortunately, it was the first epidemic disease to be completely eradicated from the face
of the earth, in large part due to the long incubation period of the disease, and in large
part due to experimentation with vaccines.
The concept of inoculation, and inoculation more or less means exposing and individual
to small amounts of a disease in order to create immunity, was well known in Africa;
India; and China by the 17th century; it gained popularity in Europe by the 18th century.
Smallpox became one of the first targets of inoculation, and the risky procedure proved
to be fairly successful – killing just a small fraction of those it infected, and resulting
in much milder forms of the disease for those who had been inoculated.
In Asia, the very first attempts at inoculation against smallpox were a practice called variolation,
and variolation was the deliberate infection of an individual with a very small dose of
the smallpox virus.
The belief was that exposure to this very small amount of the pathogen would produce
immunity to the disease and render anyone who got the disease later; it would give them
a much milder case of the disease.
So what they basically did was they took dried smallpox scabs and crushed it up into a fine
powder, that powder was then inhaled through the nostril of the person being inoculated,
and they fell prey to a very mild form of the disease.
Once they recovered, they were mostly immune to smallpox – between one and two percent
of the population of the inoculated population died from smallpox, compared to thirty percent
of the population at large.
So by 1700, the concept of variolation had spread from China into other parts of Asia;
Africa; the Ottoman Empire; and then into Europe.
In 1796, a new discovery was made by a man named Edward Jenner, a British doctor; he
noticed that women – in particular – who had developed cowpox – and cowpox was a
related virus, closely related to smallpox – but women who had developed cowpox were
largely resistant to the smallpox disease, and so he noticed this among dairy-maid populations
and decided to experiment and see if his theory was correct.
So what he did was he deliberately injected a young boy with a small dose of cowpox to
see if it, too, would create immunity to smallpox, and it was successful, leading to the establishment
of what medical historians call vaccination because this boy did not get sick vaccination
became an important practice in the European medical community.
Further testing proved conclusively that cowpox virus was able to build immunity and that
became the go-to for smallpox vaccinations.
Through global efforts, smallpox was completely eradicated by 1979, and is no longer a concern
within the world at large.
But the story of smallpox reveals the power of disease to shape world history, to shape
economies, to shape politics, and it offers lessons for the modern world in the face of
the myriad epidemic diseases that we are facing today.
Thank you.