OMG, he's got the pox!

The New York Times had an interesting article in its Friday edition (h/t to DR) about a 2-year old Indiana boy who got a viral infection from his smallpox-inoculated father:

Experts said the father, who had eczema in childhood, should never have been given the vaccine because that fact made him more susceptible to side effects like vaccinia infection. And they said military doctors should have been doubly cautious because the son, too, suffered from eczema and would have been highly susceptible to infection. Military procedures call for asking about such conditions in soldiers and their families.

Vaccinia is the live virus used in smallpox vaccine. After vaccination, the body develops a resistance to vaccinia, a disease that is generally milder than smallpox, and the resistance also works against smallpox. The injection site can spread the vaccinia virus, however, and people without strong immune systems are particularly susceptible.

Smallpox was officially declared eradicated by the World Health Organization in 1979, and inoculation of military personnel was suspended in 1990. But after the terrorist attacks of Sept. 11, 2001, and the subsequent cases of anthrax sent through the mail, the government began vaccinating military personnel and many health care workers, with 1.2 million vaccinated as of March of this year.

Since then, a handful of vaccinia cases have been reported to the Centers for Disease Control and Prevention, including one, described in the May 4 Morbidity and Mortality Weekly Report, of vulvar infection in an Alaskan woman whose sex partner was a serviceman.

I imagine that is all a little confusing, so I will briefly explain the history of the smallpox vaccine. Before 1796, the only way to protect someone against smallpox (Latin name: Variola) was inoculation, or purposefully infecting a subject with the smallpox virus in a controlled fashion. There is some debate over whether the first smallpox inoculation originated in China or India, the practice had been around for almost 600 years before it the West adopted the idea in the 17th Century.

Vaccination is the practice of introducing weak or dead pathogens into a subject and smallpox vaccine was the first ever vaccine. In the late 18th Century, British country doctor Edward Jenner realized that milkmaids who contracted and recovered from cowpox (Latin name: Vaccinia) rarely contracted smallpox. This discovery had huge implications because up until that point smallpox inoculation practices could only manage the disease's mortality rate. It could leave a person bed-ridden for up to two weeks and he/she would remain infectious for up to four weeks. Inoculation also only reduced, but could not reliably prevent smallpox's painful symptoms and sometimes permanent scaring.

This article is slightly ironic because few Americans realize that smallpox inoculation was a huge issue for the U.S. Army during the Revolutionary War (scroll down to the "The Army inoculated against smallpox"). A smallpox outbreak among the troops was a major factor leading to the failure of Benedict Arnold's expedition into Quebec in 1775. George Washington's decision to lay siege to Boston from April 1775 to March 1776 was also influenced by a smallpox outbreak in the city that year. There are even claims that British general Thomas Gage used biological warfare by sending smallpox infected Bostonians out of the city and into Washington's siege lines.

While British mandated compulsory inoculation for their troops, puritanical Americans were reluctant because the practice was seen as "going against God's will." This gave the red coats a significant upper hand during the opening years of the Revolutionary War. The Continental Army's commander, George Washington, was very cautious about exposing his non-immune troops to smallpox because of his own experience with the disease as a child. During a trip to Barbados, a smallpox infection not only robbed him of his surrogate father, Lawrence Washington, it permanently scarred his face and is probably the reason for his sterility later in life.

Washington was, therefore, a big proponent of preventive medicine in general and smallpox inoculation in particular. The Continental Congress and state governments resisted him at first, but the dire conditions and high smallpox infection rate at the winter encampment at Valley Forge forced him to take decisive action. He ordered his medical staff to begin inoculating the Continental Army and required universal inoculation for all new recruits. Many historians have credited this move, along with the training regime of Prussian drillmaster Baron Friedrich von Steuben as key to the Continental Army's turnaround in 1777-1778. One could even argue that it was "business process transformation."