Thursday, April 16, 2015

Outbreak! Time To Review The Origins Of Vaccination

The US is currently experiencing an alarming spike in the number of measles cases. Yes, measles! Don’t we have a vaccine for that virus? Yes, we do. It first became available in 1963 and was so effective that by 2000 the US declared it had eliminated measles. But in 2014, a record 644 cases suddenly appeared in 23 distinct outbreaks.

Measles is caused by a very contagious virus that infects the respiratory system, causing high fevers, coughing, and a nasty rash. Complications are common and can lead to life-threatening situations, especially in undeveloped nations. Measles has rarely been seen in the US in recent decades, but has made an alarming resurgence in 2014-15.
Unfortunately, 2015 is shaping up to be a bad year for measles, too, largely due to a multi-state outbreak propagated by so-called anti-vaxxers attending Disneyland in California. A study published last month showed that this single incident has spread measles to seven states and two additional countries and was due to parents who declined to vaccinate their children. Sadly, many of those who were infected were innocent bystanders of this misguided decision - they could not be vaccinated due to age or a legitimate medical condition.

We’ve recently discussed some of the fears the anti-vaccine movement cites to justify their opposition to vaccination, much of which stems from the completely fraudulent studies of the disgraced doctor, Andrew Wakefield. But perhaps it is worthwhile to take a trip back in time to review the origins of vaccination, which begin with the horrifying disease called smallpox.

Referred to as “the Speckled Monster”, smallpox is caused by an extremely contagious virus with a signature “dumb-bell” appearance.
Once infected with the smallpox virus, the victim becomes covered head to toe with burning pustules. The virus can also infect internal organs, which usually meant death in less than a month. Those lucky enough to survive the infection were left badly scarred and disfigured. Humanity has been struggling with this dreadful affliction since at least 1100 BC. We know this because the mummy of Egyptian pharaoh Ramses V contains the signature pockmarks caused by smallpox. Recent genetic studies suggest that the smallpox virus emerged 3000 to 4000 years ago in east Africa.

Smallpox is one of a number of infectious agents that has been a major factor in steering the course of history. Smallpox was instrumental in the conquering of the Aztecs in 1521 by Hernan Cortes and the Incas by Pizarro in 1533. Disturbingly, the early Puritan settlers in North America considered smallpox a “miracle” that purged their “New World” of the Native Americans.
The first advance in treating smallpox, which hinted at a new era of medicine, was made around 950 AD in China. Someone took note that smallpox survivors never got the disease twice and got the idea that maybe by giving someone a tiny bit of the disease on purpose would protect them from the real thing. To do this, they took the scabs from someone who looked like they were beating the infection, ground them into a powder, and blew them up the nose of someone who hadn’t caught smallpox yet. It sounds disgusting, but it worked! The scab-sniffers got very mild cases of smallpox but recovered.

By the late 1600s, the Chinese practice of delivering smallpox scabs into healthy people to prevent the disease had been refined and spread to the Turkish Empire. As shown above, a drop of pus from a person beating smallpox was scratched into the skin to “inoculate” another person and prevent him or her from getting the full-blown disease. The technique spread to England thanks to Lady Mary Wortley Montagu, wife of the ambassador to Turkey in the early 1700s.
These primitive vaccination efforts carried a great deal of risk compared to today’s methods. Since the individual was being inoculated with live smallpox virus, there was always a chance of developing full-blown smallpox and dying, along with the risk of transmitting smallpox to others. To offset the latter, England instituted “inoculation stables”, woeful low-cost sheds where peasant children were sent to stay until they either died or recovered from the smallpox inoculation.

Enter Dr. Edward Jenner. Born in 1749, he did time in an “inoculation stable” as a young lad. Smallpox may not have scarred his skin, but his experience in the stable scarred him psychologically. He decided to dedicate his life to finding a better way to beat the “Speckled Monster”. Just like the Chinese in 950 AD, keen observation is what led Jenner to an amazing breakthrough. But Jenner’s eureka moment didn’t occur in the lab or in the hospital. It came to him while observing…milkmaids.

Milkmaids had a reputation for always being pretty, with clear and smooth skin, largely because they never seemed to suffer smallpox and the extensive scarring it left in its wake. There was even a saying at the time, “If you want to marry a woman who will never be scarred by the pox, marry a milkmaid.”
In talking to milkmaids, Jenner learned that they frequently caught cowpox, a very mild disease carried by the cattle they handled every day. The milkmaids who caught cowpox would develop a few pustules on their hands that resolved on their own fairly quickly. But when Jenner proposed that cowpox was protecting the milkmaids from smallpox, most people wrote the idea off as superstitious nonsense.     

Jenner knew he had to conduct an experiment to prove the naysayers wrong. Jenner somehow convinced the parents of a young boy named James Phipps to be the guinea pig in his experiment. Jenner took cowpox pus from a milkmaid’s hand and scratched it into James’s arm. As expected, the boy developed a mild case of cowpox and recovered from it, unscathed. He called the process "vaccination" based on the Latin word for cow, "vacca". 

The next step was to see if the cowpox vaccination protected the boy from real live smallpox. So Jenner, probably with shaking hands, inoculated James with smallpox pus taken fresh from a victim at the height of the illness. Each day they waited for what must have seemed like an eternity, but James never came down with smallpox. Jenner was not only right, but his success also inspired others that we do not have to take infectious disease lying down. We can fight it.

Jenner tried 20 more times to inoculate James Phipps with smallpox, but the boy never showed a single pustule. What did James get for being used as a lab rat? Jenner built him a cottage, which is today the Jenner Museum.
So what is actually happening here? How does vaccination protect someone against an infectious disease? Unbeknownst to Jenner, we now know that microbes cause infectious disease – viruses, bacteria, fungi, and parasites. We also know that we are equipped with an immune system that battles these foreign invaders. A vaccine trains the immune system to recognize an invader before it conquers too much territory. Microbial invaders consist of foreign proteins (called antigens) that are recognized by immune cells as “non-self”. These immune cells take up to two weeks to fully kick into gear and destroy the invaders. In some cases, the invaders grow too fast or produce toxins and the immune system just can’t outpace the infection.

But when the immune system wins, it remembers the invader. If the pathogen dare challenge you again, your immune system reacts much more quickly, usually destroying the invader before you even experience symptoms. Vaccination allows your immune system to preview antigens from a weakened form of the virus (like smallpox from a pustule of a recovering patient) or a related virus that causes little or no disease (like cowpox), so it will be “primed and ready” for the real invader if it should come along.
With the first vaccination came the first anti-vaxxers. James Gillray, who drew this infamous cartoon in 1802, misled people into believing that Jenner’s cowpox inoculation would “bovinize” people, causing them to give birth to calves or have them spring out of the body. 

The word “virus” comes from a Latin word meaning “poisonous force”. Humanity has been battling these forces for thousands of years and through persistence and hard work, we finally hit upon a remarkably safe and effective antidote. To refuse the antidote may seem like a personal choice, but as evidenced by the recent measles outbreak, it puts all of us in danger.

Contributed by:  Bill Sullivan
Follow Bill on Twitter. Google+.

Majumder, M., Cohn, E., Mekaru, S., Huston, J., & Brownstein, J. (2015). Substandard Vaccination Compliance and the 2015 Measles Outbreak JAMA Pediatrics DOI: 10.1001/jamapediatrics.2015.0384

Babkin, I., & Babkina, I. (2015). The Origin of the Variola Virus Viruses, 7 (3), 1100-1112 DOI: 10.3390/v7031100

Marrin, Albert. “Dr. Jenner and the Speckled Monster”, Dutton Children’s Books, New York, 2002.

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