The Long Goodbye

Smallpox

We humans are good at creating new viruses by accident—whether it’s a new flu virus concocted
on a pig farm, or HIV evolving from the viruses of butchered chimpanzees. What we’re not so good at
is getting rid of viruses. Despite all the vaccines, antiviral drugs, and public health strategies at our
disposal, viruses still manage to escape annihilation. The best we can typically manage is to reduce
the harm viruses cause. HIV infections, for example, have declined in the United States, but fifty
thousand Americans still acquire the virus every year. Vaccination programs have eliminated some
viruses from some countries, but the viruses can still thrive in other parts of the world. In fact,
modern medicine has only managed to completely eradicate a single species of human virus from
nature. The distinction goes to the virus that causes smallpox.

But what a virus to wipe out. Over the past three thousand years, smallpox may have killed more
people than any other disease on Earth. Ancient physicians were well aware of smallpox, because its
symptoms were so clear and distinct. A victim became infected when the virus slipped into the
airway. After a week or so, the infection brought chills, a blazing fever, and agonizing aches. The
fever ebbed after a few days, but the virus was far from done. Red spots developed inside the mouth,
then the face, and then over the rest of the body. The spots filled with pus and caused stabbing pain.
About a third of people who got smallpox eventually died. In the survivors, scabs covered over the
pustules, which left behind deep, permanent scars.

Some thirty-five hundred years ago, smallpox left its first recorded trace on humanity: three
mummies from ancient Egypt, studded with pustules. Many of the oldest centers of civilization in the
Old World, from China to India to ancient Greece, felt the wrath of the virus. In 430 BC, an epidemic
of smallpox swept through Athens, killing a quarter of the Athenian army and a large percentage of the
city’s population. In the Middle Ages, crusaders returning from the Middle East brought smallpox to
Europe. Each time the virus arrived in a new defenseless population, the effects were devastating. In
1241 smallpox first came to Iceland, where it promptly killed twenty thousand of the island’s seventy
thousand inhabitants. Smallpox became well established in the Old World as cities grew, providing a
high density of potential hosts. Between 1400 and 1800, smallpox killed an estimated five hundred
million people every century in Europe alone. Its victims included sovereigns such as Czar Peter II of
Russia, Queen Mary II of England, and Emperor Joseph I of Austria.

It was not until Columbus’s arrival in the New World that Native Americans got their first exposure
to the virus. The Europeans unwittingly brought a biological weapon with them that gave the invaders
a brutal advantage over their opponents. With no immunity whatsoever to smallpox, Native
Americans died in droves when they were exposed to the virus. In Central America, over 90 percent
of the native population is believed to have died of smallpox in the decades following the arrival of
the Spanish conquistadores in the early 1500s.

The first effective way to prevent the spread of smallpox probably arose in China around AD 900.
A physician would rub a scab from a smallpox victim into a scratch in the skin of a healthy person.
(Sometimes they administered it as an inhaled powder instead.) Variolation, as this process came to