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Introduction

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Smallpox was eradicated from the Earth in 1980 after an unprecedented global immunization effort. Its status as one of only two eradicated diseases (rinderpest is the other), is a testament to the massive mortalities that are attributed to the disease. With an estimated 12 millennia of torment, smallpox claimed the lives of 300-500 million in the 20th century alone.

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Variolation and Vaccination

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Even before the colonialization of the Americas, Smallpox cases spread across the continents of Europe and Asia. The Variola virus, which caused the disease, came in two strains: minor and major. Variola Major was the more prevalent of the strains, as well as the more lethal. 25% of persons infected by Variola Major would die from the disease. On the other hand, Variola Minor was a much less severe strain, and most folks that were infected by it would recover.

The Variola Virus

After several millennia of smallpox victims, folks started to notice that there was a difference between the Major and Minor Variola strains. Better yet, they noticed that similar to survivors of the Variola Major Strain, those that had been infected with Variola Minor never became infected by smallpox again. Still better, they realized that if they intentionally infected themselves with Variola Minor in the first place, they would dramatically decrease risk of dying from smallpox.

As you could imagine, this sort of changed everything

Dramatic recreation of the first mass variolation

Ok, cool. So whenever someone's child gets sick, you host a village sleepover so everyone's kid gets it, make a big pot of chicken soup, and let the wonders of natural selection slowly but surely eliminate the big bad Variola Major.

Well, if it was actually that easy, we probably would still all have polio and mumps.

Enter Edward Jenner

Similar to smallpox, there was cowpox. Jenner intuited that "infecting" people with cowpox may develop a similar immunity as those infected with Variola Minor, without all the fun of scabs and rashes. Being from a cow, or vaca as the Spaniards would say, Jenner's process was dubbed vaccination. Legend has it that vaccination was a valuable technique that worked seamlessly for centuries until a small faction of bored n'e'er-do-wells in the USA decided to slander the process and attribute to it false side effects. Their arrogance and ignorance would cost billions in funding to quarantine and cure victims that otherwise would have been shielded from the disease...

But anyways

He deserved better than this shit...

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Oscillatory Dynamics of Smallpox Epidemics

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Well if you haven't run off to reddit for advice on how to convince your spouse to hold off on vaccinating your children, then I assume this next section will drive you to tears of boredom.

Yet in the name of knowledge, I shall persist!

So it turns out that people didn't die steadily over time from the imminent threat of smallpox. Oh no, that would be far too simple...

This nifty little chart of deaths per year by smallpox in Sweden looks pretty similar to any other chart of deaths per year by smallpox from any other place in the world. That is to say, wherever smallpox struck, it struck in fixed time intervals. Decades of modern research has been done on centuries of historical data, so I will try to summarize it in brief. Wherever smallpox would hit, it would come every 3-7 years (fixed intervals that would vary by region). A lot of different folks have tried to model the oscillations, but no published work has been able to create a concise model that doesn't involve a forcing term (myself, a classmate and, a physics professor made a simple dynamic model that we think is pretty great. Maybe it will make it into a future post). Different theories attribute the oscillations to different factors, some intrinsic and others regionally-specific.

This ones for the "All Lives Matters" Folks

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If you've even looked at the graph, my god I hope that you have, you'll notice that at some point, it became mandatory to vaccinate (I guess they were more afraid of a long, painful death than developmental disorders??). At this point, we see the magnitude of the deaths vastly decrease, yet the oscillations still remain. And you bet your dingus that this same phenomenon happened everywhere else, too.

Those pesky oscillations!

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Why do I even care

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Why should anyone study a dead disease and bother to care about the curvy waves that the data makes???

Well, smallpox was the first disease to be eradicated... and we might want to say "eradicated" because its sort of hard to say that every little microscopic Variola virus on Planet Earth is now dismembered.

Also, there are lots of diseases that have oscillatory epidemics. Understanding the math behind these epidemics can actually help control them on a large scale.

Who knows, maybe someday we can all eradicate a disease of our own! Until then...

Smallpox Girl
Variola Picture
Mud Party
Jenner
Chart
Cartoon
Meme
#steemstem-competition2