The terms “allergy” and “anaphylaxis” were created following a strange illness that affected up to 50% of vaccinated children at the close of the 1800s. This illness was simply called “serum sickness” and followed the first mass administration of diphtheria anti-toxin sera. Austrian pediatrician Clemens von Pirquet studied the illness at length and observed that the symptoms of this sickness resembled those in people who were hypersensitive to pollens and bee stings. To better describe this ‘altered reactivity’ to the sera he created the Latin derived word allergy in 1906.
In 1901, another doctor Charles Richet stumbled on the same phenomenon during attempts to vaccinate dogs to a jellyfish poison. He began by injecting dogs with trace amounts of the poison to create a level of tolerance to it. However, when he injected the animals a second time, he provoked a violent reaction that quickly killed the dogs. For this reaction he used a Latin term ana-phylaxis or anti-protection, because the outcome was the opposite from the protection that the vaccine was supposed to provide.
Richet experimented further. He quickly discovered that any protein including food proteins injected into the bloodstream results in sensitization and anaphylaxis on subsequent exposure to the food. Richet injected minute quantities of milk and meat proteins into cats, rabbits and horses and showed that anaphylaxis is a universal immune system defense.
Prior to the advent of vaccination, mass allergy such as serum sickness was unknown. At the dawn of the 20th century, doctors identified the problem of allergy as an outcome of mass vaccination – on which government relied. The dilemma of serum-induced allergy was summarized by allergist Warren Vaughan in 1941:
Serum disease, as this is called, is a man-made malady. If we had no curative serums and if there were no such thing as a hypodermic syringe with which to introduce the material under the skin, there would be no serum disease. Instead multitudes would still be dying from diphtheria and lockjaw … Thus, we find ourselves in somewhat of a dilemma, faced with the necessity for choosing the lesser of two potential evils. Warren Vaughan, Strange Malady (1941)
As vaccine ingredients became better refined to reduce the sensitizing proteins, prevalence of serum sickness decreased. With the 20th century expansion of vaccination programs and schedules to include food proteins and adjuvants, however, other unforeseen problems arose to take its place. One of these was peanut allergy (see The peanut allergy epidemic may have been precipitated by pediatric injections).