Medical Examiner

Public Health Needs the Mail

The surprising history of the USPS delivering vaccines and drugs.

An envelope with a bottle of pills peeking out
Photo illustration by Slate. Photo by Getty Images Plus.

The United States Postal Service is an essential part of our public health infrastructure. Rain or shine, the USPS delivers a significant quantity of prescription drugs to Americans of all stripes each year—almost 313 million prescriptions in 2019. Prescriptions have been sent by mail for over 100 years; the service is particularly important for the most vulnerable members of American society. The Veterans Health Administration now distributes 80 percent of prescriptions through the mail, and more than a quarter of Americans over age 60 regularly receive mail-order prescription drugs. These statistics will likely rise, as the volume of mail-order prescriptions has soared during the COVID-19 pandemic.

Now, along with the rest of the mail, prescription drugs are experiencing delays. Ensuring an adequately funded and well-run USPS is not just a matter of protecting the election through the timely delivery of mail-in ballots. It’s also a matter of protecting public health. In an announcement that they were launching an investigation into prescription drug delays, Sens. Elizabeth Warren and Bob Casey pointed out that the millions of Americans who rely on the mail for chronic health conditions like diabetes and asthma “are at grave risk.” With the opioid crisis still raging amid a pandemic, Americans in some states also now rely on the USPS for their supply of the life-saving medication naloxone. Mail-in ballots themselves are a health issue, as they offer a way to avoid the chance of infection at a crowded polling location. During in acute health crisis, the government should be investing in and supporting USPS operations and treating the service like the public health tool that it is.

There’s a long history of the federal government using the post office to respond to public health crises. In the early 19th century, the post office took on a formal public health role when it became the primary means of transporting the smallpox vaccine. Edward Jenner, an English doctor, discovered in 1796 that exposing patients to cowpox, a harmless bovine virus, conferred immunity to smallpox. In 1800, physician Benjamin Waterhouse became the first American to acquire the vaccine, after Jenner agreed to mail it to him in the form of dried threads crusted with pus. Waterhouse then mailed some of his supply to other American physicians, who in turn sent it to their colleagues. The vaccine circulated widely in this way. Within two years it had reached the Mississippi Territory, then still a remote backwater, though one that could nonetheless receive mail, and therefore a vaccine.

At the time, vaccinating a population was a little more complicated than administering shots. Doctors would scrape the dried vaccine pus they had received in their mailboxes into a cut on a patient’s arm. Then, once the patient developed a cowpox lesion—a pustule that took about a week to form—the physician would scrape pus from the first patient’s lesion into another patient’s incision. They found those patients through the mail, too, with newspaper advertisements. Patients arrived en masse at dispensaries, schools, private homes, or even bookstores, where vaccinating physicians had set up shop. Still, maintaining a consistent supply of cowpox was difficult. The wild virus was rare, especially in the United States. Accordingly, some communities and states established central locations where a physician would maintain the vaccine and distribute it—in person or by mail—to other vaccinators in the area.

One enterprising doctor, James Smith, saw the potential to develop a vaccine distribution system at a federal level. Smith wrote to President James Madison in 1809 on the ongoing problem of smallpox, the spread of which could be “easily, checked by the Vaccine, at any Season of the year, with a little industry.” He argued that “with proper directions” people who couldn’t easily access a physician could, if supplied some pus, simply administer the vaccine to themselves. In 1813, Congress passed “An Act to Encourage Vaccination,” which established Smith as the nation’s first “vaccine agent.” His role was to preserve the vaccine and “to furnish the same to any citizen of the United States … through the medium of the post office,” free of postage charge. Once appointed, Smith circulated a notice to newspaper editors across the U.S. In it, Smith explained that he would send instructions, an instrument to perform vaccination, and an inspection certificate that verified the authenticity of the vaccine to anyone who applied.

This was an unprecedented piece of legislation—and one of questionable constitutionality, as matters of public health were generally regulated by states rather than the federal government. It is difficult to know exactly why the federal government passed the act. Perhaps, with the War of 1812 raging, Madison worried that smallpox could devastate the Army, as had happened during the early years of the Revolutionary War. It is likely that Madison recognized the importance of a consistent vaccine supply to protect both the army and the general population. Outbreaks often accompanied periods of armed conflict, during which soldiers traveled together and lived in close quarters.

The Vaccine Institute, as Smith’s project was called, was the product of his singular vision, but he did not work alone. As historian Richard R. John has shown, Smith depended upon an “army of postmasters.” The post office was a formidable force, greater in size than the actual Army. It was well respected and, by association, imbued the vaccine with a metaphorical stamp of governmental and medical legitimacy. By all accounts, the vaccine distribution system worked smoothly. That is, until 1821, when Smith accidentally sent smallpox itself to Tarboro, North Carolina, instead of cowpox, causing a deadly outbreak. Smith was swiftly fired and, after a fierce congressional debate, “An Act to Encourage Vaccination” was repealed. The experiment had ended, but not without demonstrating just how useful the post office could be for promoting public health, if used wisely.

The post office might have been part of a failed public health effort, but it didn’t lose importance as a public health tool. Physicians continued to rely on the post office to transport the smallpox vaccine to one another, as well as to advertise their services in newspapers, circulate medical literature, and exchange correspondence about new theories and techniques. The post office was the primary means of distributing health information in the United States for a long period of time. New agencies, like the Centers for Disease Control and Prevention, have taken on increased responsibility for public health messaging. But in times of crisis, the federal government has continued to rely on the USPS. In 1988, for example, amid the HIV/AIDS epidemic, Surgeon General C. Everett Koop sent a pamphlet titled “Understanding AIDS” to every American home. The pamphlet explained that HIV was contracted only through direct contact with bodily fluids, in an effort to encourage safer practices and destigmatize the illness.

As a key federal civilian logistics agency with an enormous nationwide physical footprint, the USPS could be mobilized as a trusted partner in combating the current pandemic by distributing information, masks, and testing materials. The government has taken small steps in this direction, mailing Americans postcards encouraging them to social distance. Maybe you’ve sent loved ones masks in the mail or ordered medications online to avoid risking a trip to the store when case counts were high. To enable people to remain connected—and healthy—while staying physically apart during the ongoing pandemic, the USPS requires resources. A pandemic is a particularly bad time to kneecap it.