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Smallpox
description
Smallpox was probably the greatest single incentive towards
the precipitation of modern western science and to the onset of
the field of immunology. Smallpox has been with us for as long
as we have historical records. It is a virus, called the variola
virus, that possibly mutated from cattle to be capable of infecting
humans. It is suggested that as humans became less nomadic and
settled into sedentary farming practices, the cattle domesticated
for food were probably the contact point for transfer of the smallpox
agent.
There are several substrains of smallpox, some more virulent
than others. Typically the death rate from infection with smallpox
was around 25%, a three in four chance of survival. However, more
aggressive strains pushed the death rate to around 40% in some
outbreaks. With no defense against this threat it is perhaps not
surprising the ancient world became very fatalistic and were resigned
to the fact of infection. Smallpox was part of life, and death.
Symptoms of smallpox infection first included a fever, headache,
a feeling of perpetual weakness and exhaustion associated with
joint pain. After several days the visible signs of smallpox developed.
First a rash and then development of skin blisters. In severe
cases the blisters became so dense as to coalesce into giant pustules.
If the individual survived the pustules left scars or "pocks".
Death was slow, painful and probably came as a relief for those
who were severely affected. Those who were weaker, the very young
and the very old died swiftly.
We rarely hear about smallpox today. It is no longer a threat
to the human race. So much so that vaccination against it is no
longer required. The last infection of smallpox was recorded in
1977 and currently the only known sources of small pox are languishing
in two laboratories, one in the US and one in Russia. The final
chapter of the smallpox saga is bing written right now. The World
Health Organization will decide whether the two research laboratories
should destroy their smallpox stocks. The final decision on its
destruction will come any day now.
Human
history of smallpox and the birth of modern science
Arguably the person who brought variolation to Europe was Lady
Mary Wortly Montagu. As an aristocrat she was no stranger to court
of King George I and as a resident of London in the early 1700s
she was at considerable risk of contracting smallpox. Smallpox was
no respecter of social status and Lady Montagu was infected but
recovered with permanent pocked skin and loss of hair from the scarring.
Soon after her recovery her husband, Edward Wortly, Montagu was
posted to Constantinople (Istanbul) as ambassador. While there,
Lady Montagu learnt of smallpox inoculation as practiced by Turkish
physicians. The transfer of smallpox as a form of controlled infection
had expanded west from China along the traditional trade routes
to Constantinople. The technique was called variolation. This was
derived from the name of the infective agent which is the variola
virus. The risk of death from variolation was around 2%, a risk
but a considerable improvement on the death rate for uncontrolled
infection.
Clearly impressed and with her own experiences uppermost in her
mind, Lady Mary had her son inoculated with smallpox. Her son survived
and despite regular exposure to smallpox epidemics never (that we
are aware of) became infected again. On her return to London the
publicity her actions caused came to the attention of many physicians
and ultimately the Royal Family. Although the medical practitioners
were extremely resistant to the idea, King George decided that his
children should be inoculated. However, first he wanted to see the
effects and dangers of inoculation for himself. In 1721 Six volunteer
condemned prisoners were inoculated with pus from a smallpox infected
individual. The notion that using humans in experimental trials
may be unethical was unheard of at the time. The prisoners were
in effect the property of the King at that time. Fortunately, all
the prisoners survived the inoculation and their prize was a full
pardon and release from prison. Further experiments were conducted
for the Royal Family including the inoculation of orphans (Originally
the Royal Family wanted an entire orphanage inoculated. Again, they
were seen as crown property!). Eventually the Royal Family was convinced
and Princess' Amelia and Caroline were inoculated and survived.
The reporting of the Royal Family's use of variolation resulted
in a wave of copy cat inoculations in the aristocracy.
However, variolation was still limited in its use. The practice
met resistance because the general population were not prepared
for this scientific advance. There was still a risk of death, variolation
could potentially spread the disease as inoculated people were temporarily
carriers for smallpox and the greatest resistance came from the
church who condemned the practice as heathen and immoral. In the
US the resistance may have stemmed in part from racism. Inoculation
was known to have been practiced by slaves. In essence society had
not developed to the degree of scientific and social sophistication
required to make the jump in comprehending how variolation might
work and why its use may have been an advantage. This is a problem
that has dogged medical developments to this day and we will touch
on the subject again I am sure.
Edward
Jenner
Enter stage left Edward Jenner. Contrary to popular belief Jenner
was not at first interested in smallpox and did not consciously
set out to make any medical advance. He was interested in the possibility
that animal diseases may spread to other species and possibly humans.
This made Jenner something of a social pariah. His ideas went against
popular belief and the church. Also, he was not medically qualified
which gave him a low social status in the eyes of the medical community.
Jenner believed that cow pox was derived from horses and from
there it was a small step to the idea that smallpox was derived
from cowpox. We know little about Jenner's development of thought
but it would seem that he arrived at the notion that smallpox and
cow pox were related and that inoculation with cowpox might confer
resistance to smallpox. He was well aware of the practice of variolation
and he was also aware of the belief in the rural community that
infection with cowpox led to immunity against smallpox.
In 1796 Jenner, collected pus from cowpox sores on the hands of
milkmaid Sarah Nelmes and inoculated eight year old James Phipps.
Phipps developed a fever but nothing more. Then Jenner inoculated
Phipps with pus from active smallpox. The boy developed no reaction
to the smallpox inoculation. Jenner conducted several similar successful
experiments but met with resistance when trying to publish his work.
Eventually Jenner had to publish his experimental results at his
own expense. At first derided and laughed at, with the suggestion
that cowpox inoculation would make people grow horns, the idea was
taken up by a few enlightened physicians. Their confirmation of
Jenner's observations gradually led to acceptance of "vaccination".
Cowpox is the result of the "vacca" virus. Hence the term
"vaccination" (Vacca is Latin for cow).
Vaccination was adopted over variolation. Its advantages were
clear. Conference of resistance to smallpox without risk of death
as was possible with variolation. Within fifty years of the discovery
most European countries had initiated compulsory vaccination. Success
was at first highly variable depending on the strain of cowpox virus
used and how it was applied. Without knowledge that they were dealing
with a virus, vaccination techniques developed through trial and
error. That pus which seemed to confer greater resistance was propagated
in cattle and collected. The "booster shot" also developed
when it was realized that resistance to smallpox through vaccination
was not always life long.
The enforced programs were probably the significant factor in
spread of vaccination over variolation. The same reasons for resistance
to variolation were still present in the general population. However,
the medical community had developed to the extent that its influence
had the ear of the politicians. While vaccination programs may have
led to greater social maturity in acceptance of scientific principle
it still did not provide a suitable environment for development
of an understanding that the human body may have a defense system
against infection. Jenner, never attempted to explain why or how
vaccination might work, it just did and that was good enough.
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