BOSTON — APRIL 1721 — When the HMS Seahorse sailed into port, it carried goods from Barbados, a crew of hearty sailors, and one stowaway — smallpox. Three sick men were quarantined but when the pox broke free, Cotton Mather saw the Devil at the door. "The grievous calamity of the small pox has now entered the town.”

By May, Boston was under siege. A doctor described the symptoms: “Hemorrhages of blood at the mouth, nose, fundament, and privities. . . Blisters and the skin stripping off. . . Some who live are cripples, others idiots, and many blind all their days.”

But Cotton Mather offered hope. Mather was a devout Puritan, his world half the Devil’s, half the Lord’s. He had backed the Salem Witch Trials and spent his Sundays haranguing sinners from his pulpit. But while other preachers called smallpox “punishment for sin,” Mather had lost too much to accept any disease as divine.

Measles had claimed his wife and three of his children. Seven other children later took sick and died. Mather, fascinated by the latest in medicine, was desperate to rid Boston of this “Destroying Angel.”

On June 2, speaking to doctors, Mather described what he had learned from his slave. Onesimus “told me that he had undergone the operation which had given something of the smallpox and would forever preserve him from it, adding that was often used in West Africa.” Mather then read letters from London and Constantinople describing “the operation.”

Doctors scoffed. A slave remedy? Give a healthy man a mild dose of the dreaded pox? Surely such a “cure” would spread the plague. But one Harvard professor, after confirming Onesimus’ story with other slaves, decided to try.

On June 26, Zabdiel Boylston made a small cut in his son’s arm and rubbed it with dried pus from the pox’s less fatal variant. Then Boylston inoculated his own slave and his son. All came down with fevers but all recovered.

Mather was encouraged, but word of this “cure” leaked. From the New England Courant: "Some have been carrying about instruments of inoculation, and bottles of poisonous humor, to infect all who were willing to submit to it. Can any man infect a family in the morning, and pray to God in the evening that the distemper will not spread?"

All of Boston debated. Doctors called this “variolation” pure folly. Preachers wondered whether the pox might be “one of the strange works of God; and whether inoculation of it be not a fighting with the most High."

By August, half of Boston’s 11,000 had smallpox. “The Arrows of Death are flying among us,” Mather wrote. His son, Samuel, whose chambermaid at Harvard had died of the pox, begged for inoculation. Mather balked. “If he should after all die by receiving it in the common Way, how can I answer it?” As he wrestled with his conscience, the anti-vaxx movement raged.

Mather saw “a strange Possession of the People. . . They rave, they rail, they blaspheme; they talk not only like Idiots but also like Franticks. And not only the Physician who began the Experiment, but I also am an Object of their Fury.”

Finally, Mather had no choice. He had to protect his son. “I could not answer it unto God if I neglected it.” He then watched in horror as the boy got sicker. Had “Sammy” contracted the fatal variant before the procedure?

Come September, Samuel’s fever subsided, but then Mather’s two daughters, one pregnant, took sick. As the maples turned blood red, Nancy recovered. But two days after giving birth, Abigail succumbed. She was the 11th of Mather’s children to die. Crushed by another loss, he named her baby “Resigned.”

On through the fall, Zabdiel Boylston inoculated whoever would agree. But Boston was becoming “a City full of Lies, and Murders, and Blasphemies.” Then just before dawn on November 14, a homemade bomb shattered Mather’s parlor window. A note was attached:

"Cotton Mather, I was once of your meeting, but the cursed lye you told of - you know who, made me leave you, you dog, and damn you, I will inoculate you with this, with a pox on you!"

The bomb did not explode — “this night there stood by me the Angel of the God” — but the damage was done. Boylston, after getting death threats, inoculated a final 15, then ended his campaign. All 15 recovered.

By February, the pox had run its course. Some 850 were dead, thousands scarred for life. Yet of 247 inoculated, only six succumbed. Boston slowly settled. Had the lesson been learned?

Decades later, British doctor Edward Jenner, noting that milkmaids who contracted the mild cowpox never got smallpox, had an idea that would save millions. Jenner scraped cowpox pustules from a milkmaid’s hands, then injected them in the arms of his gardener’s son. Even when exposed to smallpox, the boy stayed safe. The word “vaccination” comes from the Latin for cowpox.

In 1958, the World Health Organization set a goal of eradicating smallpox. Within twenty years, with little or no opposition, the disease that once killed a half million each year was conquered. Gone. No more to plague us. Draw your own conclusions.

THE PREACHER, THE SLAVE, AND THE VAXX