Buckle up, we are taking a road trip to discover vaccines.
A great place to start talking about vaccines is at the beginning. And chances are good the beginning is not where any of us think it is.
Throughout history, there have been many illnesses and diseases. But two have caused perhaps the most deaths and illnesses throughout the whole of time. Measles and Smallpox. Thought to be the "same" thing, in 0910 a Persian physician was the first to publish a written account titled “On Smallpox and Measles” in which he describes the two diseases as being distinct and unique from each other. Which meant that two different ways of treating them would be needed, based on their specific characteristics.
But the story of vaccines does not begin with the first vaccine in 1798 - Edward Jenner’s use of material from cowpox pustules to provide protection against smallpox. Rather, it begins with the long history of infectious disease in humans, and in particular, with early uses of smallpox material to provide immunity to that disease.
Evidence exists that the Chinese employed smallpox inoculation (or variolation, as such use of smallpox material was called) as early as 1000 CE. In the late 1600s Emperor K'ang Hsi, who had survived smallpox as a child, had his children inoculated.
There were two methods of inoculation known to be used in those days. Grinding up smallpox scabs and blowing the matter into the nostril or scratching matter from a smallpox sore into the skin.
As infectious diseases swept through nations the need for a way to halt these diseases and treat them was being pursued. The Chinese method of inoculation hadn't caught on and/or people were suspicious of its ability to stop the disease. Smallpox and measles were joined by epidemics of pertussis (whooping cough), typhoid fever, diphtheria, yellow fever, scarlet fever, cholera, and polio...to name a few.
According to historical records, between 1545 and 1817 various parts of the world experienced smallpox, whooping cough, measles, typhoid fever, diphtheria, and yellow fever epidemics.
An epidemic is a disease that affects a large number of people within a community, population, or region. A pandemic is an epidemic that's spread over multiple countries or continents.
Presumably, due to an increase in travel and transportation advancements, pandemics became the concern starting with a cholera outbreak in 1817 that swept through India, Asia, and then traveled throughout the world leading to seven major cholera pandemics, each lasting several years, between 1817 and present day. Yes! Present-day!
Prior to the gaining popularity of early inoculation methods, the treatment for these diseases consisted of quarantining, providing comfort measures, attempting to bring down high fevers, bloodletting, inducement of vomiting, alcohol-laced with herbs, and praying that the person wouldn't die or suffer from physical damage due to the disease.
Once again, the Chinese made vaccine headlines (figuratively of course) when Emperor K’ang verbalized support for inoculation in a letter to his descendants in 1661. Having survived a case of smallpox before he became Emperor he wrote:
“The method of inoculation having been brought to light during my reign, I had it used upon you, my sons and daughters, and my descendants, and you all passed through the smallpox in the happiest possible manner…. In the beginning, when I had it tested on one or two people, some old women taxed me with extravagance and spoke very strongly against inoculation. The courage which I summoned up to insist on its practice has saved the lives and health of millions of men. This is an extremely important thing, of which I am very proud.”
In the 1700s variolation started to be practiced more and more as word spread that it worked. Fewer people were dying and that was looked upon favorably.
But what's variolation? Isn't it vaccination? Aren't they the same?
Variolation (inoculation) served as a natural precursor to the discovery of vaccination. The development, adoption, and improvement of infectious disease responses are messy processes – there's never a single “eureka” event. There always has to be a precursor, or two, before arriving at the end result.
This method of treatment was used strictly with smallpox outbreaks as the disease provided a visible form of the infection to use.
With variolation, a small amount of the pus from a person infected with smallpox was placed into the skin of an uninfected person. The thought was that the disease would then take hold in the previously uninfected person but in a mild form. It was discovered to be less dangerous to contract it through inoculation than to contract it naturally.
This method of safeguarding against dangerous diseases was never risk-free, nor did advocates of the method claim it to be risk-free. But it greatly reduced the mortality rates. Between 1% to 2% of those variolated died as compared to 30% who died when they contracted the disease naturally.
Inoculation gained popularity in the 1700s.
In 1721 Cotton Mather, thanks to the information his African slave provided him, suggested physician Zabdiel Boylston try the inoculation method as an outbreak of smallpox was ravaging Boston. 248 people were variolated and of those 248, 3% - or 6 people - died. Of those left to the disease and vulnerable to its symptoms 14% died. Thus, variolation had come to the Americas.
Meanwhile, across the pond, Lady Mary Wortley Montagu had been introduced to "engrafting" in Turkey and when arriving back in England in 1721 requested it be done to her two-year-old daughter. Her son had been engrafted while they were in Turkey. Thus, variolation had come to England.
Both Mather and Lady Montagu would come under considerable criticism for advocating variolation, a practice that slowly began to spread as its ability to protect against smallpox became apparent even in light of its fatality rates and the discovery that variolated individuals could pass the disease on to others.
In the 1770s rumors began circulating about a disease called cowpox. People who regularly worked with cattle were claiming that their exposure, and subsequent infection, to cowpox inoculated them against smallpox.
Cowpox is an uncommon illness in cattle, usually mild, that can be spread from a cow to humans via sores on the cow. During an infection, dairy workers may have pustules on their hands. Sufferers can spread the infection to other parts of the body.
Around 1774 farmer Benjamin Jesty inoculated his wife and two sons with matter from a cowpox lesion on one of his cows.
Jesty, having already contracted cowpox, believed himself protected from smallpox infection. When a serious smallpox epidemic hit his Dorset village, he, from his “great strength of mind,” took it upon himself to protect his family. His wife and children survived, and the boys, when challenged with smallpox inoculation in 1789, showed no symptoms.
Mr. Jesty, however, had no interest in systematically testing his methods or publishing his results, and so his finding was largely forgotten. Upon his death, his wife had his tombstone inscribed, “the first person (known) who introduced the cow-pox inoculation.”
In the 1770s Jenner had also heard the rumors about using cowpox to inoculate against smallpox but he was still in the thick of his medical school studies and residency program.
However, in May 1796 Dr. Jenner inoculated eight-year-old James Phipps with matter from a cowpox sore on the hand of a milkmaid. Phipps suffered a local reaction and felt poorly for several days but made a full recovery. So in July 1796, Jenner inoculated Phipps with matter taken from a fresh human smallpox sore, as if he were variolating the boy, in an attempt to challenge the protection from cowpox. Phipps remained healthy.
Jenner next demonstrated that cowpox matter transferred in a human chain, from one person to the next, provided protection from smallpox.
For the next couple of years, Dr. Jenner continued to test his idea on patients and saw great success. He wrote a paper for the Royal Society of his findings but they rejected it. So Jenner self-published a pamphlet called “An Inquiry into the Causes and Effects of the Variolae Vaccinae, a Disease discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of the Cow Pox.” It outlined Jenner’s success in protecting James Phipps from smallpox infection with material from a cowpox pustule, in addition to 22 related cases. At first, the news was received quietly if received at all. But that changed when an associate of Jenner's, Henry Cline, used dried vaccine material provided by Jenner to demonstrate once again that vaccination with cowpox material prevented future smallpox infection.
The vaccine started to gain traction and quickly became preferred over variolation for its improved success and safety.
But, didn't Jenner engraft James Phipps? He took the pus from the infection and placed it under the skin of an uninfected person. That's what people had been doing for years by 1796! So how was what Jenner did different than what everyone else was doing?
So, how are variolation and vaccination different from one another?
Both are using infected pus to infect, in the hopes of immunity, uninfected people.
The difference is subtle but very important. Variolation used viral matter from smallpox patients, usually pus from a light case of smallpox. Jenner's vaccination, meanwhile, used matter from the milder cowpox virus. As a milder disease carrying the same immunities, cowpox matter was much safer. Both methods are also called inoculation because inoculation is the process of introducing a small amount of viral matter into the body in order to teach the body’s immune system to fight off the virus, thus making the patient immune to future infection.
So step one in what would become today's modern vaccination was successfully tested and completed. As is the case with any invention, the first workable treatment would be replaced with an improved option and that cycle would continue until we arrived at the year 2020 and the need for a new vaccine presented itself.
But, that part of the story is much later.
Between Jenner's successful test run of the smallpox vaccine in 1796 and 1879, the vaccine creation and delivery methods stayed the same. In order to meet the demand vaccine farms were created, voices of government endorsed the method, variolation was outlawed in certain parts of the world, and other infectious diseases were being dissected in hopes of developing vaccines.
In the last decade of Jenner's life smallpox mortality rates in Britain declined by approximately 43% thanks to the vaccine.
So what happened in 1879 to push the vaccine forward yet again toward what we know it as today?
Between his birth in 1822 and 1879, Pasteur grew up and became an accomplished academic. In 1831 he witnessed firsthand a rabies outbreak and that gave him the desire to solve that problem as well as others. Between 1840 and 1847 Pasteur earned at least 4 degrees. He was found in 1849 teaching Chemistry. In 1854 Pasteur began studying fermentation which would end up being crucial to the next step in modernizing vaccines. Despite a stroke that left his left arm and leg permanently paralyzed, Pasteur persevered in his research and produced the first laboratory-developed vaccine in 1879. It was a vaccine for chicken cholera (Pasteurella multocida).
A happy accident led to this step in vaccine production as Pasteur's assistant didn't follow instructions and the bacteria was exposed to oxygen. Turned out that the oxygen exposed bacteria weakened the disease enough to make it effective in providing protection against the full-strength bacteria.
When Louis Pasteur died in 1895 his life's work had accomplished advancements in vaccine production; he had proved that germs cause disease; he developed vaccines for anthrax and rabies, and he created the process of pasteurization.
{You can find all the sources I used by clicking here.}
