Revolutions in Medicine

All modern vaccines, from polio to Covid-19, trace their origin to the smallpox vaccine developed by Edward Jenner in the 1790s. By introducing inactive or weakened versions of viruses, vaccines train the body’s immune system to defend itself against those viruses, thereby preventing the spread of infectious disease. In the 230 years since Jenner, vaccines have been developed for nearly 30 diseases and are estimated to have saved 154 million lives in the past 50 years alone.

Smallpox was a devastating disease that plagued humanity for millennia. With a fatality rate of at least 30%, it is believed that smallpox killed 500 million people over 3000 years. It is no surprise, then, that the first medical publication in the American colonies gave advice on dealing with smallpox outbreaks, seen in facsimile here.

Those who survived smallpox were often left deeply scarred and sometimes blind. Survivors were also observed to be less susceptible to reinfection and much less likely to die if infected again. Noting that infection generated immunity, medical practitioners attempted to prevent smallpox through variolation (from variola, the Latin name for the virus), exposing healthy people to smallpox, through inhaling powdered scabs or introducing material from sores under the skin, using instruments like a fleam to create an incision. This resulted in a milder infection, with a 1-2% mortality rate. The practice spread from Asia to Britain and its American colonies in the 1700s. In 1777, George Washington ordered variolation of the Continental Army, the first medical mandate in American history.

Even with variolation, smallpox continued to kill millions of people in the 1700s. It was known that milkmaids who developed mild cowpox infections were often protected from the more severe smallpox. Using this knowledge, on May 14, 1796, English physician Edward Jenner introduced pus from a milkmaid’s cowpox blisters (illustrated here) into cuts on the arm of a young boy, who did not catch smallpox when later exposed to it. Jenner called his innovation “vaccination” from vacca, Latin for cow. In 1881, Louis Pasteur (who developed three vaccines himself) suggested that “vaccine” should be broadened to mean all such inoculations, not just that for smallpox, in honor of Jenner.

Smallpox vaccination quickly gained traction in the Western world. By 1900, many countries had mandatory vaccination policies. Despite this, smallpox remained a global threat. A pamphlet was published by the Illinois State Board of Health in response to an outbreak of a new virulent form of the disease. Its insistence that “Small-pox is a preventable disease” and the many photos of people with smallpox who were “never vaccinated” demonstrates the knowledge of the vaccine’s benefits set against the ongoing fight to stop the spread of the devastating disease through vaccination campaigns.

Within 100 years of Jenner’s vaccine, many Western countries had virtually eliminated smallpox. By 1953, it had been completely eradicated in North America and Europe. Despite this, 300 million people still died of smallpox in the 20th century alone, due to its spread in regions with underdeveloped healthcare systems.

In 1967, the World Health Organization announced the Intensified Smallpox Eradication Program after a failed first attempt at global eradication. Advances in technology for storing the vaccine and in the needles used to administer it bolstered the program, making vaccination more cost effective and medically effective. Most importantly, affected countries committed to massive surveillance, containment, and vaccination campaigns.

The World Health Organization Regional Office for Africa published this pictorial guide in 1970 to help newly-recruited staff diagnose smallpox and distinguish it from chickenpox. Smallpox was still endemic in many African countries in the late 1960s, as seen in the map below. Publications like this contributed to local efforts to quickly identify cases and prevent the spread of the disease. This item comes from the collection of Ralph Paffenbarger (1922-2007), MD, DPH, a 1947 alumnus of the medical school who worked on smallpox eradication with the United States Public Health Service in the 1970s.

The World Health Organization’s Intensified Eradication Program was a monumental success. Maps from WHO’s official report show the number of countries with endemic smallpox shrinking from nearly three dozen in 1967 to just one in 1976. Only 10 years after the program began, the last naturally occurring case of smallpox in the world was recorded, and on May 8, 1980, WHO declared that "the world and all its peoples have won freedom from smallpox.” It remains the only infectious disease eradicated from the world’s human population.

Author Fanny Burney’s description of a mastectomy gives voice to centuries of surgical patients who were subjected to excruciating pain before the invention of modern anesthesia. People tried to avoid surgery at all costs, enduring infections, letting tumors grow to massive sizes, and even dying rather than undergoing a painful operation. Surgeons did use sedatives like opium and alcohol, but they were unreliable and hard to control. It wasn’t until the mid 1800s that doctors began to use inhaled anesthetics, kicking off a century of experimentation.

By the 1840s, scientists had synthesized three compounds that would transform patients’ experience of surgery—ether (by the 16th century), nitrous oxide (1772), and chloroform (circa 1831). All three had been noted for their narcotic effects (and were sometimes used recreationally) but were not employed as anesthesia until the 1840s. On October 16, 1846, dentist William T.G. Morton anesthetized a patient with ether at Massachusetts General Hospital before an operation to remove a tumor from his neck (illustrated here). This marked the first public demonstration of an effective surgical anesthetic.

Once surgeons began publishing about new anesthetics, others began to experiment with them. This included Edmund Andrews, MD (1824-1904), a founder of the Feinberg School of Medicine and Professor of Surgery for 40 years. In one experiment, he added free oxygen to nitrous oxide, which made the oxygen more easily absorbable by the body, rather than being bound to nitrogen, helping prevent asphyxia. Andrews also studied over 200,000 surgical cases that used different anesthetics and compared the results—ether resulted in only 1 death per 23,000 uses while chloroform caused 1 death per 2700. Fifty years of Andrews’s case books show that he frequently used ether in his surgical practice.

As the adoption of inhaled gas anesthetics spread, a new concern emerged: patient safety, particularly airway management. Patients were at risk of asphyxiating when the muscles of the mouth and throat relaxed during unconsciousness. American anesthesiologist Paluel Flagg dedicated himself to this cause. He invented many kinds of equipment including an endotracheal tube and an artificial airway. He shared his methods and equipment in a popular textbook on anesthesia, one of the earliest American books on the subject.

General anesthesia with inhaled gas was the default method until the end of the 1800s when doctors began experimenting with cocaine injections to selectively numb parts of the body. Cocaine’s potential for addiction and short duration of action led to the development of new regional anesthetics like procaine (known by the trade name Novocain). In the 1920s, French anesthesiologist Gaston Labat helped popularize regional anesthesia in the United States. He introduced pioneering spinal anesthesia techniques in his textbook, which became the essential text for American practitioners.

Doctors tried administering many drugs intravenously in the 1800s, including ether and chloral hydrate, which had toxic and damaging effects. It took the creation of a new class of drugs for the true potential of IV anesthesia to be realized. Barbiturates were first synthesized in 1864 but not used clinically until the 20th century. Hundreds of derivatives were created, notably Somnifen (the first barbiturate administered intravenously) in 1921 and short-acting thiopental (seen here under the brand name Pentothal) in the 1930s. In this 1943 book, leading anesthesiologist Christopher L. Hewer describes many IV barbiturates and the technique of using them.

In less than 200 years, anesthesia has evolved into a technologically advanced, safe, and effective medical tool; improvements in safety and perioperative care have lowered anesthesia-related mortality by almost 200 percent since 1940. Experimentation and innovation in the 19th century also allowed for corresponding advancements in the practice of surgery, making it safer and more effective as well. These twin developments have resulted in a proliferation of surgical procedures in the 21st century: 40-50 million surgeries are performed annually in the United States alone and general anesthesia, with its combination of drugs that induce unconsciousness, immobility, and pain relief, is administered to 60,000 patients each day.

On November 8, 1895, while conducting experiments with electricity and vacuum tubes, German physicist Wilhelm Röntgen noticed a green glow on a nearby fluorescent screen. Further experiments showed that the rays that created the glow could pass through most substances but left shadows of solid material like metal and bone. He called his discovery “X” rays due to their unknown nature. At the end of the year Röntgen’s discovery was published in the journal of the Physical-Medical Society of Wurzburg. This X-ray of the hand of the Society’s chairman Albert von Kölliker was taken on January 23, 1896. Röntgen received a Nobel Prize in Physics for his discovery in 1901.

Within two weeks of Röntgen’s publication, physicists and physicians around the world began their own experiments with X-rays, which they often referred to as “Röntgen rays” in his honor. They immediately saw the diagnostic potential of noninvasively seeing into the body. On February 7, 1896, Chicago surgeon James Burry (an 1875 alumnus of the medical school) became the first documented person in the city and the first physician in the country to take X-ray images, called radiographs. Four days later, he became the first surgeon to use radiographs to guide their surgery, locating and then removing a small bullet from a man’s hand.

Only 9 months after Röntgen’s discovery, the first American textbook on the use of X-rays was published, by William J. Morton, the son of William T. G. Morton of ether fame. The book focuses on the method and apparatus for creating X-ray images. Morton devotes a mere 20 pages to the X-ray’s “surgical value” which is almost exclusively diagnostic: viewing bone fractures, identifying disease in soft tissue, and locating foreign objects for surgical removal. Only a page and a half are given to the X-ray’s “curative action” on bacteria. Morton did note irritation of the X-ray technician’s skin, “somewhat of the nature of sunburn,” hinting at the unforeseen dangers of radiation exposure.

Early experimenters did seek therapeutic as well as diagnostic uses for X-rays. Due to technical limitations, the rays could not reliably and effectively reach diseases deep within the body, but they were found to be useful in treating inflammatory skin and joint diseases and visible tumors. This book was written by American physician Francis H. Williams, an early proponent of the use of X-rays for therapeutic purposes. Only 5 years after Röntgen’s discovery, Williams’s section on therapeutic uses of X-rays is 60 pages long and includes diseases like lupus (seen here) and squamous cell carcinoma.

By the 1920s, technical advances led to stronger, more stable X-ray beams, which could penetrate deeper into the body, allowing for more effective cancer treatment. The medical school’s Department of Radiology (seen in the image below left, ca. 1930) formed around this time. William Moss, MD, taught radiology at Northwestern for 14 years and was a pioneer of radiation oncology. His textbook was one of the first to deal specifically with radiation treatment of cancer. He shows where radiation beams should be directed and the results of treatment for breast cancer, which could previously only be treated by removing the breast (see Fanny Burney’s description of a mastectomy without anesthesia in the "Anesthesia" section).

The X-ray continues to be an important diagnostic and therapeutic tool in the 21st century. Radiation therapy contributes to nearly half of all cancer cures and is used on over 50% of cancer patients. As with many medical and technical innovations, though, disparities in access to these life-saving treatments still exist.

Medical revolutions like epidemiology, vaccines, anesthesia, and X-rays can only be globally successful if they are accessible to all. Dedicated efforts like WHO’s smallpox vaccination program or anti-smoking campaigns based on the epidemiology of lung cancer demonstrate how widespread access to medical knowledge and innovations can change the world.