By the turn of the 20th century, pneumonia was indeed a fearsome and ever-present menace, having overtaken tuberculosis as the "Captain of the Men of Death" in this country. Largely ascribed to infection with the bacteria pneumococcus, pneumonia carried an approximately 25 percent mortality rate in the pre-antibiotic era, killing off the young and old alike. During the 1918 influenza epidemic, many of the deaths stemmed from "secondary" pneumonia infections that attacked already flu-damaged lungs. Efforts to treat pneumonia with somewhat effective antiserum in the 1930s led to the public depiction of pneumonia as an "emergency," necessitating the rapid infusion of serum early in the course of the disease, when it was deemed most effective. But with the advent of the sulfa drugs in the late 1930s, and antibiotics in the 1940s and 1950s, pneumonia lost its fearsome persona. Already in 1945 an Upjohn ad for penicillin was entitled "We've come a long, long way in pneumonia," while a 1951 Lederle ad for its "broad-spectrum" antibiotic Aureomycin carried the tagline, "Thank heavens it's only pneumonia!"
The conquest of pneumonia thus epitomized the power of ascendant medical and pharmaceutical professions alike, and the public perception of pneumonia changed in turn in the post-World War II era. The apparent epidemiology of pneumonia would change as well. A host of organisms – viral, bacterial, fungal – would be found to cause pneumonia. At the same time, a host of factors – age and immune status of the patient, whether the patient had recently been hospitalized or not – would be found to be useful in determining how a patient should be treated. "Pneumonia" has continued to evolve both microbiologically and as a disease category, as medicine, microbes, patients, and society alike have changed.
Despite such complexity, pneumococcal pneumonia in particular remains an important and potentially lethal form of pneumonia, as well as a cause of ear and sinus infections, and meningitis. In the immediate post-war enthusiasm over antibiotics, the first effective pneumococcal vaccine was largely ignored; but as pneumococcal pneumonia's potential dangers (especially among those in whom it had invaded the bloodstream) were again appreciated, a pneumococcal vaccine would again be introduced by the late 1970s. There are now vaccines for both children and adults. The conjugate vaccine for children, introduced on the market in 2000, has been particularly transformative, not only reducing the incidence of childhood pneumonia, pneumococcal meningitis, and inner ear infections, but likely leading to "herd immunity" and a reduction in pneumonia among adults (who are exposed less to dangerous pneumococci) as well. Here are the Centers for Disease Control and Preventions' Advisory Committee on Immunization Practices' recommendations on immunization.
Finally, what about Hillary Clinton's pneumonia? First, while poorly timed, the fact of its development signifies very little about her underlying or future health. Pneumonia may be more prevalent among those over age 65, but pneumonia can afflict patients of any age. Second, "pneumonia" itself is a diverse category, occurring in a diverse range of patients, so it is difficult to predict how quickly Clinton will recover, though she seems to be improving rapidly. Third, as historian Barron Lerner has written, celebrity illnesses have long drawn attention to particular diseases. It will be interesting to see if pneumococcal vaccination rates increase in the coming months, when folks of nearly all ages should be getting their flu shots as well!
Scott Podolsky is a primary care physician at Massachusetts General Hospital, associate professor of global health and social medicine at Harvard Medical School, and director of the Center for the History of Medicine at the Countway Medical Library. He is the author of Pneumonia before Antibiotics: Therapeutic Evolution and Evaluation in Twentieth Century America, and The Antibiotic Era: Reform, Resistance, and the Pursuit of a Rational Therapeutics, both published by Johns Hopkins University Press.