Theme: Urgency created by wars and epidemics combined with the can-do attitude of the twentieth century triggered medical advancements that extended American life expectancy and improved the overall quality of life for the American population.


Throughout the twentieth century, scientists made numerous advancements in the field of medicine that improved the quantity and quality of American life. They were driven by the pressure of time created by wars and epidemics to discover medicine that would save lives and decrease the amount of war casualties. Among the medical advancements with the most significant implications were the discovery of penicillin, the influenza vaccine, the polio vaccine, and the first human heart transplant.

Alexander Fleming discovers penicillin

Before the use of penicillin during World War II, many soldiers died from bacterial infections rather than directly from their wounds.
The most significant medical advancement that affected American life was the discovery of penicillin, one of the earliest identified and most widely used antibiotics. Penicillin was discovered by Scottish bacteriologist Alexander Fleming working at St. Mary’s Hospital in 1928. He observed that colonies of bacterium could be destroyed by Penicillium mold, demonstrating that the mold released an antibacterial agent (Bellis). This principle later led to the invention of an unprecedented medicine that could kill certain types of disease-causing bacteria within the body. Fleming published his findings in 1929, stating that his discovery could have therapeutic properties if it could be produced in quantity, but the significance of his breakthrough was unknown at the time (Bellis).

In 1938, Howard Florey, Ernst Chain, and Norman Heatley expanded on Fleming’s work at Oxford University. The scientists worked to develop methods of cultivating, extracting, and purifying enough penicillin to establish its value as a drug (Fogal). By the time their investigations began to show results, World War II had commenced and proceeded to drain England of its industrial and government resources. The British scientists could not utilize factory resources in order to cultivate the quantities of penicillin needed for clinical trials on humans and turned to the United States for help, relocating their research in 1941 to protect it from the German bombardment of England (Bellis)(Fogal). As the devastation of the war amplified, interest in penicillin increased in laboratories, universities, and drug companies in both Europe and the United States. Research continued on how to grow the mold efficiently in order to produce penicillin in the mass quantities that would be needed for millions of soldiers. The pressure of time pushed scientists, who knew they were in a race against death since many soldiers were not dying directly from their wounds, but from infections that set into those wounds (Fogal).

Success came in 1941, when the scientists were able to drastically increase the yields of penicillin. By 1943, the required clinical trials were performed and penicillin proved to be the most effective antibacterial agent to date. Penicillin production quickly increased, and it was available in quantity to treat Allied soldiers wounded on D-Day (Bellis). Enough penicillin was generated to treat seven million patients per year by the closing stages of the war (Wong). As its accessibility skyrocketed, its price dropped from twenty dollars per dose in 1943 to fifty-five cents per dose by 1946 (Bellis). The impact of penicillin was instantaneously evident with regard to the war. Of the millions of soldiers who had died in combat in pre-penicillin World War I, many had died from infection of pneumonia. Death rate from pneumonia in the American army decreased from eighteen percent in World War I to less than one percent in World War II (Wong). The discovery of penicillin diminished the amount of American casualties from infection and extended and improved the quality of American lives.

Thomas Francis discovers first influenza vaccine

Citizens were required to wear gauze masks in public during the influenza pandemic of 1918, reminded by this rhyme:
“Obey the laws
And wear the gauze
Protect your jaws
From Septic Paws”
A second remarkable medical advancement that affected life in America was the invention of the influenza vaccine in 1945. At the closing stages of World War I the most destructive pandemic recorded in world history ravaged the earth, infecting a fifth of the world’s population and twenty-eight percent of all Americans with influenza (Billings). The virus was the most fatal for those between the ages of twenty and forty, its effects so severe that the average life expectancy in the United States was depressed by ten years. Half of the American soldiers who died in the war in Europe fell to the influenza virus rather than to the enemy (Billings). Just as the war affected the path of influenza as it followed its human carriers along trade routes and shipping lines, influenza affected the course of the war, leaving entire fleets too sick to fight.

World War I placed great importance on science, as the United States and European governments depended on scientists to derive vaccines and reduce casualties due to disease and battle wounds. The war caused governments to implement propaganda campaigns and nationalism spread as citizens began to accept government authority, enabling public health departments to easily step in and take restrictive measures (Billings). Gauze masks were to be worn in public, stores could not hold sales, funerals were limited to fifteen minutes, and signed certificates were required to enter some towns. Those who disregarded the influenza ordinances had to pay fines enforced by officers (Billings). These conditions created by the war along with the current social attitudes and ideas led to public encouragement of scientific application, reflecting new allegiance to science in the wartime society. Immunologists raced to develop a vaccine that would terminate the epidemic.

The influenza vaccine took years to discover and required the cooperation of many individuals. Thomas Francis, the director of the commission on influenza United States Army Epidemiological Board, was the first American to isolate the human influenza virus (Joachim). He and Jonas Salk researched a vaccine for influenza at the University of Michigan, and over the course of several years the vaccine was perfected. The vaccine had many side effects when it was first derived in 1945, but by the mid 1950’s Thomas Francis declared the vaccine safe for worldwide distribution (Joachim). The availability of the influenza vaccine was essential to producing healthy families during the baby boom of the 50’s that followed, lengthening and improving the quality of American lives.
"The 1918 has gone: a year momentous as the termination of the most cruel war in the annals of the human race; a year which marked, the end at least for a time, of man's destruction of man; unfortunately a year in which developed a most fatal infectious disease causing the death of hundreds of thousands of human beings. Medical science for four and one-half years devoted itself to putting men on the firing line and keeping them there."
— Journal of the American Medical Association final edition of 1918, 12/28/1918

Jonas Salk Discovers First Polio Vaccine

Heartbreaking posters of children on crutches or in iron lungs, the machines that helped those lungs were paralyzed to breathe, circulated during the polio outbreaks of the 1950’s.
Another medical advancement that impacted American life occurred in 1955, when Jonas Salk discovered the first polio vaccine. Earlier, in 1921, outbreaks of poliomyelitis began to plague America. This virus enters the body through the nose or mouth and travels to the intestines, where it incubates (Maybury). A few days later, patients may be asymptomatic or show flu-like symptoms, but all patients can pass the disease on to others at this stage. The virus next enters the bloodstream, and the body must produce antibodies to destroy it (Maybury). In most cases the patient can produce antibodies to stop the virus and acquire lifelong immunity; however, one percent of infected people develop the paralytic form of polio. In these cases, the virus reaches the brain and spinal cord where it multiplies and obliterates nerve tissue (Maybury). The disease becomes either spinal, affecting the limbs, or bulbar, affecting the lungs so that patients cannot breathe. Polio could be spread through contact with infected feces or through infected droplets traveling through the air, in food, or in water (Maybury).

President Franklin Roosevelt, who suffered from the spinal paralytic form of polio, led the fight against the disease by boosting public awareness and promoting research for a cure. Although polio never annihilated vast quantities of the American population as influenza did, it was a fearsome and highly contagious disease that affected both the rich and poor and occurred in terrifying outbreaks (Maybury). Before the twentieth century, immunity to the disease was developed primarily during infancy because sanitation conditions were poor and infants were frequently exposed to polioviruses. Ironically, when hygiene methods improved, infants no longer developed antibodies to fight the virus and were at risk to contract the disease in later childhood and adulthood (Maybury). Children were the most susceptible and parents panicked, keeping their children from schools and other public facilities.

In 1952, Jonas Salk produced a successful vaccine using a mixture of the three types of the virus, which was followed by immense clinical trials of the vaccine in the United States. The results of the trials were dramatic – cases of polio fell enormously in the vaccinated test groups (Maybury). In 1955, the government granted permission for the vaccine to be distributed to children. In 1960, there were 2,525 cases of paralytic polio in the United States; by 1965, the number dropped to 61. There has not been a single case of polio in the United States since 1979, and by 1994, polio was declared eradicated in all of the Americas (Maybury). The discovery and use of the polio vaccine significantly impacted the life expectancy and quality of life of Americans.

Christiaan Barnard performs first heart transplant

53-year-old Lewis Washkansky, who suffered from chronic heart disease, was the first man to receive a heart transplant.
An additional major medical advancement that changed life in America was the first successful human heart transplant, which was performed by South African surgeon Christiaan Barnard in 1967. He was inspired by heart disease, which was a dominant cause of death and remains the leading cause among adults over age 60 in the United States (Eure)(Leading). Perfection of heart-lung machine technology, which handled the patient’s heart and lung functions while surgery was performed, was the gateway to cardiac surgery and enabled Barnard to execute the procedure (Cape). Lewis Washkansky, the recipient of the first heart transplant and a sufferer of heart disease, lived eighteen days after the operation with a new heart that functioned normally. The setback was that after the surgery, he was given drugs to suppress his immune system and prevent his body from rejecting the new heart – these drugs left him susceptible to sickness, and caused him to contract double pneumonia. The development of better anti-rejection drugs during the 1970’s made transplantation more practical. Barnard continued to perform heart transplants, and by the late 1970’s many of his patients were living up to five years with their new hearts (First).

Successful heart transplant surgery is very commonplace today, though it is an expensive procedure that is out of reach for some and finding appropriate donors is extremely difficult. Despite an increasing number of potential recipients, the number of heart donors has reached a plateau – more than 5,000 heart transplants take place each year worldwide, though an estimated 50,000 people are candidates for the procedure (Eisen). This lack of donors means that healthcare providers must strictly assess who should receive a heart transplant. The foremost reason for cardiac transplantation is to improve survival, followed by to enhance quality of life (Eisen). Survival among transplant recipients has significantly improved as a result of advancements in treatments that suppress the immune system and prevent infection. Heart transplantation and other methods of cardiac care have extensively lengthened and improved the quality of American lives.


Each of these medical advancements, along with many others, has significantly affected the life expectancy and quality of life of Americans. The byproduct of these medical advancements is that they have changed the social fabric of America. There is current debate over the quality of life of elder people, and how long people should continue to work in their elder years. As the baby boom generation grows older, it will be required to work longer because there will be less young citizens to support the influx of people with social security. Today it is common for people to follow second career paths, and sometimes work into their 70’s. This would have been impossible without the medical improvements of the twentieth century, and I believe it is a positive outcome because it gives people more purpose to be productive in their elder years. Scientists continue to research cures for diseases that weren’t as well-known earlier in the twentieth century such as cancer, which is the current second leading cause of death among adults over 65 in the United States following heart disease (Eure)(Leading). Because people no longer die of diseases that vaccines have been discovered for, cancer eventually kills many elders. If cancer were to be eradicated as polio had been, the life expectancy in the United States would continue to significantly increase.

Works Cited

Bellis, Mary. "History of Penicillin." Inventors. The New York Times Company. Web. 14 June 2011.

Billings, Molly. "The 1918 Influenza Pandemic." June 2005. Web. 14 June 2011.

Cape Gateway. "Chris Barnard Performs World's First Heart Transplant." Cape Gateway. Web. 18 June 2011.

Eisen, Howard J. "Heart Transplantation." Ed. Sharon A Hunt and Susan B Yeon. UpToDate Inc. Web. 18 June 2011.

Eure, Marian A. "Top Causes of Death Among Adults Over 65." Senior Health. The New York Times Company, 24 May 2010. Web. 18 June 2011.

"First Human Heart Transplant." History Made Every Day. A&E Television Networks. Web. 18 June 2011.

Fogal, Robert. "Penicillin: the First Miracle Drug." Utah State University: Intermountain Herbarium. Ed. Patricia Rogers. 8 Dec. 2006. Web. 14 June 2011.

Joachim, M.J. "Who Discovered the Influenza Vaccine?" Helium - Where Knowledge Rules. Helium Inc., 10 Feb. 2009. Web. 14 June 2011.

"Leading Causes of Death." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 23 May 2011. Web. 18 June 2011.

Maybury Okonek, Bonnie A. "Development of Polio Vaccines." Access Excellence at the National Health Museum. Ed. Linda Morganstein. Web. 14 June 2011.

Wong, George. "Penicillin, The Wonder Drug." University of Hawaii at Manoa Botany. Fall 2003. Web. 14 June 2011.