Vaccinations were common in the 19th century

Medical history: history of vaccination

From variation to vaccination

Smallpox - called "flaking" in its lighter form - used to be common in Europe and Asia; mortality was estimated to be 15 percent, and as with (other) childhood diseases, one disease protected from a second disease.

In Asian countries it has been customary for centuries to infect people not suffering from smallpox by inoculating the secretion from the pustules of smallpox patients, whereupon they mostly fell ill comparatively easily and were protected from smallpox for their future lives.

The British envoy wife, Mary Wortley Montagu, got to know this procedure in Constantinople in 1718 and won over English doctors to use it in England. Many orthodox doctors accepted the variolation (after "variolae", the Latin name for smallpox) despite its risks and tried to develop it further by reducing the virulence of the smallpox secretion with various methods.

Country doctor Edward Jenner (1749 to 1823), a student of the experimental surgeon John Hunter, took a new path. He observed that people who were infected with a particular vesicular rash on the udder of cows ("cowpox") never got smallpox.

In order to prove a causal connection, he carried out the following decisive experiment in 1796: He vaccinated an eight-year-old boy, who had previously been spared from smallpox, with the pustular secretion of a maid who had suffered from cowpox, whereupon he fell ill. Six weeks later he inoculated the boy with smallpox secretion and, as expected, the boy did not become ill.

Introduction of mandatory vaccination ...

The vaccination (after vacca = cow) was now established in Europe in no time at all. Following the Jenner model, the vaccine - the lymph - was obtained from people who were newly infected with cowpox. With this "humanized" cowpox lymph, the yield was greater and the shelf life longer than with original cowpox lymph; in both cases, however, the shelf life was only a few days. The vaccine arrived fresh and effective in America by vaccinating several children one after the other during the sea voyage.

The Kingdom of Bavaria and the Grand Duchy of Hesse introduced compulsory imprisonment as early as 1807, while other German states - including Prussia - did not apply any compulsion in this regard. Only after an epidemic of smallpox in Germany in 1870/71 claimed 125,000 deaths was the Reich Vaccination Act passed on April 8, 1874, which stipulated that children must be vaccinated both in the first and in the twelfth year of life. Failure to comply could result in fines and imprisonment.

... and their opponents

There had always been opponents of vaccination, the philosopher Immanuel Kant had warned that with cowpox people would also be inoculated with "animal brutality". However, after the introduction of compulsory vaccinations, the protest became louder. Local "Vaccination Compulsory Associations" were formed, from 1876 the periodical "Der Impfgegner" appeared, and in 1908 the "Association of Vaccination Opponent Doctors" was founded. In Germany, the movement found support from the life reform movement and was eventually absorbed into it.

Even if the arguments against vaccination were predominantly of a fundamental nature, there was also justified criticism of the health risks. The use of humanized cowpox lymph harbored the risk of transmitting other infectious diseases, especially syphilis. In order to eliminate this risk, this procedure was banned in Germany in 1885. The vaccine has since been obtained directly from calves and young cattle.

In 1979 the WHO declared the world smallpox free. This spared the experts the problem of developing a vaccine without the risk of BSE.

Anthrax and rabies vaccine

The development of vaccines was given a new impetus by researchers such as Louis Pasteur (1822-1895), Robert Koch (1843-1910), Emil von Behring (1854-1917) and Paul Ehrlich (1854-1915). They owed inspiration to the new science of bacteriology; Above all, however, empirical strategies proved to be fruitful, especially since viruses, the causative agents of numerous infectious diseases, could not yet be identified at the time.

In long-term studies, Pasteur bred attenuated anthrax bacteria, which he used in 1881 in a successful large-scale experiment on cattle and sheep.

In the case of rabies, Pasteur proceeded according to a similar principle, although he did not know the pathogen: He transferred the materially intangible poison (lat. "Virus") of rabies from the dog to a number of rabbits, whereby it weakened so that it no longer caused rabies when it was transferred back to a dog, but protected it from disease if it was bitten by a rabid dog.

In 1885 a person was successfully treated with a tetanus serum for the first time.

Diphtheria serum

A milestone in the fight against infectious diseases was the development of diphtheria serum. This was preceded by the discovery of the diphtheria bacillus (1882) and the diphtheria toxin six years later by Emile Roux and Alexandre Yersin at the Pasteur Institute. The phenomenon, which was soon observed, that a body could be infected with bacteria without the toxin being detectable and without it becoming ill, was a mystery.

Emil von Behring came to the conclusion that an individual who is immune to diphtheria has antitoxins, "poison-destroying" substances, in his blood. He had previously observed that iodoform has an antitoxic effect by canceling out the poisonous effect emanating from pus bacteria without killing the bacteria themselves, and concluded that an organism immune to diphtheria toxin itself produces an antitoxin that is comparable in its effects to iodoform. It had to be possible to obtain an antitoxic serum from immunized animals and to treat patients with it.

Corresponding animal experiments seemed to confirm this theory, which had no idea about the complex immune system. Then Roux produced a diphtheria serum by immunizing horses, with which he treated diphtheria patients with great success from 1894 in Paris. In Berlin, v. At the same time, Behring set up an animal barn to produce the serum he needed, but the demand was so great that the Hoechst paint factory commissioned a large-scale plant for the production of diphtheria serum in November 1894.

Vaccination with toxoids

In the Institute for Serum Research and Testing in Frankfurt am Main, which was founded in 1898, Paul Ehrlich further developed his groundbreaking theories about the effects of poisons and antidotes and drugs. He differentiated haptophoric and toxophoric groups in the toxin and postulated that a side chain of the drug acts as a receptor for the toxin, rendering it harmless.

In 1897 Paul Ehrlich was able to show that a toxin is largely harmless if it is deprived of its haptophoric group; the isolated toxophore group, which he called "toxoid", he inactivated with formaldehyde. The tetanus vaccine was developed on this basis.

In order to replace passive immunization with active immunization in the fight against diphtheria, v. Behring developed the TA vaccine from 1913, a mixture of antitoxin (A) and unchanged toxin (T), which was used for decades but is now obsolete due to a relatively high rate of side effects. A toxoid is also used today for vaccination against diphtheria.

A wrong path: tuberculin

To treat tuberculous patients, Koch created tuberculin in 1890, a nutrient solution of tuberculous bacteria mixed with glycerine and reduced to a tenth of its volume. After euphoric initial findings, it was found that the preparation was ineffective; it could not further increase the efficiency of the immune system, which was already maximally activated by the infection, one spoke of the "tuberculin dizziness".

Calmette and Guérin worked with a Bacillus (BCG) whose pathogenicity was weakened by breeding, but which only partially fulfilled the expectations placed on it; it is still used today in people who are at high risk of infection, especially newborns. Otherwise, the pushing back of tuberculosis is partly due to the many prophylactic measures, partly to modern antibiotics.

Oral vaccination is cute

Oral vaccination against poliomyelitis is the last great success story of protective vaccination in Western countries. Jonas Salk (1914-1995) developed the vaccine by growing attenuated viruses in cultivated monkey kidney cells and inactivating them with formaldehyde before application.

The vaccination, which was mandatory in Germany since the early 1960s, also led to the protection of non-vaccinated people, as the attenuated virus displaced the wild virus from the population.

The introduction of vaccinations against influenza and against infections with Haemophilus and pneumococci was not particularly spectacular - although very useful. What many patients are eagerly awaiting now is the development of a vaccine against AIDS.