1827: The "No child left unvaccinated" act becomes the law for Boston schools.

Smallpox was a deadly, disgusting disease, with the nasty habit of killing one-third of those who contracted the disease, and maiming those who were fortunate enough to survive it.

Boston's declaration came just three decades after Edward Jenner discovered in 1796 that blister pus from those infected with the less-deadly cowpox could be used to immunize humans from smallpox.

Following Massachusetts' lead, cities and states across the United States passed laws throughout the 19th century requiring citizens and schoolchildren to be vaccinated (.pdf) against smallpox in hopes of eradicating the disease.

Such rules weren't universally loved, and in 1905, the Supreme Court heard a challenge to Massachusetts' mandatory vaccination law. The court ruled, in Jacobson v. Massachusetts that the city of Cambridge had the right to require everyone over 21 to be vaccinated against smallpox or be fined $5 (about $120 in today's money).

The court disputed Jacobson's argument that a compulsory vaccination violated his

Constitutional rights, ruling that "the liberty secured by the Constitution of the United States to every person within its jurisdiction does not import an absolute right in each person, to be, at all times and in all circumstances wholly free from restraint."

Despite smallpox's simple treatment and the laws mandating it, smallpox is estimated to have killed between 300 and 500 million people in the 20th century. In what is considered a triumph of modern medicine, the World Health organization eradicated smallpox in 1979 after a decade-long search-and-destroy mission.

To this day, all states require students to be inoculated, typically against diphtheria, measles, rubella and polio. However, most states provide exemptions for parents who have religious, medical and sometimes philosophical reasons for not having their child immunized.

Scientifically unfounded fears that vaccines cause autism have recently led many parents, particularly those in wealthy areas like Marin County, California, to forgo vaccinations, despite the risks of disease.

Source: Various

Image: Smallpox creates pustulent boils that, if they don't kill, can disfigure.

Courtesy Library of Congress