During the last decade of the nineteenth century, diphtheria was known as the “strangling angel of children.” The bacterial disease choked young victims by forming a thick, gray membrane across their throats and releasing a deadly toxin that paralyzed hearts and damaged kidneys. In just a few days, entire families lost multiple children to medical science.
With the discovery of serum therapy, which utilizes blood serum containing specific neutralizers to neutralize bacterial toxins, that terrifying reality changed dramatically.
Physiologist and microbiologist Emil von Behring was awarded the Nobel Prize in Physiology or Medicine in 1901 for his work on diphtheria antitoxin therapy.
However, this historic triumph hides a complex story of collaboration and professional erasure. Serum therapy was possible due to the fundamental discoveries made by Behring’s brilliant Japanese colleague, Kitasato Shibasaburō. Aside from receiving the Nobel Prize, great wealth, and noble status, Kitasato-whose laboratory mastery made it possible to isolate tetanus and diphtheria toxins-was systematically overlooked by Western scientific bias and commercial greed.
Throughout the course of this detailed examination, we will learn about Emil von Behring, the groundbreaking discovery of antitoxins in Robert Koch’s Berlin laboratory, Kitasato Shibasabur’s exclusion from Nobel history, and how serum therapy transformed modern immunology.
Robert Koch’s Early Life and Influence
The Birth of Emil Adolf von Behring took place on March 15, 1854, in Hansdorf, West Prussia (now Ławice, Poland). Despite growing up in a large, financially struggling family, Behring was able to secure a college education by serving in the military.
He enrolled at the Army Medical Academy in Berlin in 1874, which offered free medical education in exchange for military service. As a military physician, he served in West Prussia and Poland for several years after earning his medical degree in 1878.
In his military service, Behring developed a keen interest in epidemiology, wound sanitation, and the action of chemical disinfectants.
Joining the Institute of Infectious Diseases
Prussian military recognized Behring’s analytical abilities and assigned him to work under Robert Koch, the titan of bacteriology who had discovered tuberculosis, cholera, and anthrax bacteria.
After joining Koch’s Institute for Infectious Diseases in Berlin in 1889, Behring became the head of that institute. Premier researchers from around the world visited the laboratory, which was an intellectual powerhouse. Under a government sponsorship, Kitasato Shibasabur arrived in Berlin in 1885 as a brilliant young Japanese scientist.
A Breakthrough in Serum Therapy
The field of bacteriology faced a major theoretical puzzle when Kitasato and Behring began working together in Koch’s laboratory:
Despite the bacteria themselves staying localized at the site of infection (such as a wound or the throat), diseases such as tetanus (Clostridium tetani) and diphtheria (Corynebacterium diphtheriae) could produce lethal symptoms throughout the human body.
Diphtheria bacteria produced a powerful soluble poison, or toxin, that circulated through the bloodstream to cause organ damage in 1888.
The Crucial Technical Mastery of Kitasato
To study the toxins of tetanus and diphtheria bacteria, scientists had to isolate pure cultures in the lab first.
Tetanus bacteria are strict anaerobes, which means they die immediately when they come into contact with oxygen. Clostridium tetani cultures had been attempted for years by Western scientists without success.
It was Kitasato’s breakthrough in 1889 that allowed the isolation of the tetanus bacillus in pure culture for the first time ever.
Kitasato and Behring began injecting small, non-lethal doses of bacterial toxins into rabbits, guinea pigs, and horses with Kitasato’s pure tetanus cultures.
The Joint Discovery of Antitoxins (1890)
The duo made a revolutionary observation: animals inoculated with small doses of toxin developed a protective substance in their blood.
When the researchers injected the liquid portion of an immunized animal’s blood (serum) into an untreated animal, the recipient became completely immune to lethal doses of the toxin. Furthermore, injecting the serum into an already sick animal neutralized the poison and cured it.
Blutserumtherapie (blood serum therapy) and the term antitoxin were introduced in December 1890 by Behring and Kitasato in their landmark joint paper on tetanus. Behring published a second paper applying the exact same principle to diphtheria a week later.
Human medicine was transformed by the discovery:
- Passive Immunity vs Active Immunity: It established the principle that pre-made antibodies from an immunized animal can be transferred directly into a sick body to provide immediate protection.
- By targeting and neutralizing bacterial poisons floating in the bloodstream, serum therapy eliminates bacteria rather than trying to kill directly inside the body with toxic chemicals.
Kitasato Shibasabur’s Sideline
Even though they worked together in their early research, Emil von Behring and Kitasato Shibasabur’s professional paths diverged once commercial potential and academic honors entered the picture.
Hoechst Commercialization Agreement
In order to mass produce diphtheria antitoxin, Behring partnered with the German chemical giant Farbwerke Hoechst.
In an effort to maximize his personal gain, Behring negotiated a lucrative commercial contract that gave him massive royalties on every vial of diphtheria antitoxin sold worldwide. In these negotiations, Behring excluded Kitasato from patent agreements and financial royalties, taking full intellectual property credit for diphtheria.
As Kitasato returned to Japan in 1892 to establish the Institute for Infectious Diseases in Tokyo, Behring amassed a fortune from Hoechst royalties and became a professor at Marburg University.
The 1901 Nobel Prize Snub
Physiology and medicine’s first Nobel Prize was awarded in 1901 by the newly established Nobel Foundation to the following individual:
Emil Adolf von Behring for his work on serum therapy, especially its application in diphtheria, by which he has opened a new path in medical science and created a weapon against illness and death in the doctor’s hands.”
The Nobel committee omitted Kitasato’s name despite his contribution to the isolation of the tetanus toxin, co-authorship of the initial antitoxin paper of 1890, and development of the experimental framework for serum therapy.
Kitasato’s exclusion is attributed to several factors by historians of medicine:
- Eurocentric bias in Western scientific academies during the early twentieth century: These academies typically minimized or overlooked the contributions of researchers of other cultures.
- Isolation in Category: The Nobel Committee isolated just diphtheria (published by Behring under his own name), rather than the joint work on tetanus.
- The Behring Self-Promotion: Behring actively campaigned for his own candidacy, positioning himself as the sole inventor of serum therapy and downplaying his Japanese collaborator’s technical advances.
While Kitasato went on to become the undisputed father of modern Japanese bacteriology, discovering the plague bacillus (Yersinia pestis) in 1894 and founding modern public health institutions in East Asia, his Nobel snub in 1901 remains one of the most glaring omissions in medical history.
Taking care of Europe’s children through mass production
Despite its personal controversies, diphtheria antitoxin had a profound and immediate impact on public health globally.
Using Behring’s horse serum, chemist Paul Ehrlich refined and concentrated it in 1894, standardizing dosage strength and making large-scale clinical administration safe for children.
The mortality rate plummeted overnight in European hospitals after diphtheria antitoxin was introduced in the mid-1890s:
- In hospital wards before antitoxin therapy, diphtheria killed between 50% and 80% of infected children.
- The mortality rate for children has fallen to under 10% to 15% following the widespread implementation of serum therapy.
In 1901, Behring was granted nobility in the Prussian state, allowing him to add the prestigious “von” to his surname. He was hailed across Europe as the “Savior of Children.”
The Serum Immunology of Emil von Behring is one of his most important achievements
A foundation for modern immunology and therapeutic blood products was laid by Emil von Behring’s contributions:
| Focus Area | Scientific Innovation | Historical Impact |
| Concept of Passive Immunity (1890) | Co-discovered that serum from immunized animals neutralizes bacterial toxins in recipients. | Established the field of serum therapy and humoral immunology. |
| Diphtheria Antitoxin (1891) | Developed serum treatments specifically targeting diphtheria toxin. | Reduced child mortality from diphtheria by over 70% worldwide. |
| Industrial Production | Partnered with Hoechst to mass-produce standardized serum from horses. | Created the commercial blueprint for pharmaceutical biological products. |
| First Medicine Nobel (1901) | Awarded the inaugural Nobel Prize in Physiology or Medicine. | Set the historical precedent for recognizing immunological breakthroughs. |
A Divided Legacy: Final Thoughts
As a professor at the University of Marburg, Emil von Behring established his own research enterprise, the Behringwerke, which produced vaccines and sera for military and civilian applications. His death occurred on March 31, 1917, when he was 63 years old.
A deep admiration and a critical nuance surround Behring’s scientific legacy today.
As a result of his brilliant application of serum therapy, hundreds of thousands of young lives were saved and the modern era of immunology was opened. As well, history has restored Kitasato Shibasaburō to his rightful place beside Behring as a true co-creator of antitoxin science.
Though scientific breakthroughs are often remembered through single names on prize citations, real progress almost always results from cross-cultural collaboration and joint intellectual courage.
