As yet, no one has had the boldness to inoculate human brings with living bacteria and to imitate Nature in her manner of killing off all the sensitive subjects in order to preserve the rest. This was formerly done by inoculation with small-pox but the unfortunate results of the practice compelled its abandonment among civilized people. Even Nature's immunity is not perfect in all diseases, as many a patient with his sixth attack of grippe or third pneumonia or fortieth year of hay fever has learned most feelingly; and this irregularity of natural immunity bears directly on the proposal to immunize patients against hay fever by small and increasing doses of the offending pollen. If the natural disease does not confer lasting immunity, you will have some difficulty in conferring lasting immunity artificially, as the immunologist is just now discovering. His immunity passes off so rapidly that he is now searching for a method of immunizing that can be carried on for many years without tying the patient to a laboratory for life. It is right here that I believe that homœopathy has valuable methods that can be applied to the situation.
But we must not jump to conclusions. Because we can immunize successfully against one disease, it does not follow that the same methods will immunize against another disease. Each disease is a problem in itself and may require its own methods. Nor because we can immunize the guinea-pig in the laboratory, does it follow that the same methods are applicable in the human patient. The only proof that we can immunize against hay fever is to immunize against hay fever. So, to the subject!
Passive Immunity. The first man to attempt to apply the methods of modern immunity to hay fever was Dunbar, of Hamburg, in 1903, with this pollantin. He attempted to duplicate in hay fever the triumph of antitoxin in diphtheria by injecting a horse with increasing doses of pollen until the horse became immune to large doses of pollen and his blood full of antibodies. Dunbar expected to confer passive immunity on the hay fever patient by transferring to him this horse serum with its antibodies. There is no better example of the rule that each disease requires its own methods of immunity. While diphtheria antitoxin is harmless to the diphtheria patient, the serum of the pollen-immunized horse nearly killed the first patient Dunbar tried it on, who happened to be his assistant, a sufferer from hay fever. It is probable that pollantin is based on the wrong principle, that hay fever is not, like diphtheria, a poisoning by a toxin to be antidoted by an antitoxin. However, to Dunbar belongs the credit of first attempting to put the treatment of hay fever on a scientific basis and he introduced the method of testing the patient that has been followed by all later workers, dropping the pollen extract in the eye.
In the Centralblatt für Bakteriologie, Referate, xxxvi, s. 453, there is an account of a most unseemly quarrel between Dunbar and Weichardt, the latter claiming that before leaving Hamburg, he suggested the idea of pollantin to Dunbar. Weichardt has since put on the market another hay fever specific, called graminol, which is the blood-serum of cattle that have fed on the offending grasses during the hay fever season. The theory is that the blood of the cow contains antibodies to those grasses and that passive immunity can be conferred on the hay fever patient by transferring those antibodies to his blood.
This is the old, old experiment that has been tried so many times in many diseases and has so often failed. It reminds us of the many attempts to confer on the tuberculosis patient the natural immunity possessed by the jackass by injecting the patient with the blood serum of that friend of man. The result of these experiments left some doubt as to who merited most the name of jackass, the doctor, the patient or the patient beast. Both pollantin and graminol have been praised highly in Germany but neither of them have succeeded so well in this country. Perhaps a shrewd advertising campaign had something to do with it; for the combination of a German scientist and his manufacturer can give points to any Yankee in exploiting the public with sure cures for the sick.
Active Immunity. In active immunization, the real pioneers, after Mithridates, were the homœopaths, who, for many years, have given small doses of poison ivy to prevent ivy poisoning and small doses of the poisons of infectious diseases to prevent and cure those diseases; but the homœopath did not realize the transient nature of immunity and the necessity for continuing the treatment for many months or years, nor did he adopt the principle of increasing the dose to the point of toleration.
The first to attempt active immunization and cure of hay fever by injecting extracts of the pollen that causes the disease appears to have been Noon, working in Wright's laboratory in London. The work was continued by Freeman, their work being reported in the Lancet, 1911, i, page 1572 and ii, page 814. They found the English spring form of hay fever due to the pollen of grasses. By dropping extracts of various pollens into the patient's eye, after the manner of Dunbar, they concluded that their patients were most sensitive to timothy grass and they used timothy extract exclusively in the treatment. Freeman states explicitly that a patient immunized against timothy grass is immune to all other grasses of that season; that it is unnecessary to immunize him to each particular grass, thus differing from some of our American observers who use the skin reaction to determine the particular pollens to which the patient is sensitive and inject every one of those pollens in the treatment.
Independently of these British observers, Karl Koessler, of Chicago, in 1910, attempted to immunize patients against hay fever by injecting pollen extracts. Like Noon and Freeman, he used the eye reaction to test his patients and found them most sensitive to rag weed. Just as the Englishmen had used only timothy grass in their cases, Koessler used rag weed exclusively. His work is reported in his article on Hay Fever in Forchheimer's Therapeusis, Volume V and also in the Illinois Medical Journal, 1914, page 120.
Selecting the Pollen. The Skin Reaction. The next step in the development of the pollen treatment was to substitute the skin reaction for the eye reaction in testing the patient's sensitiveness to various pollens. The advantage of the skin reaction over the eye reaction is that it permits testing many pollens at the same time and does not distress the patient as does a sharp eye reaction.
While Noon and Freeman selected the one typical pollen of spring, the timothy grass pollen, and Koessler selected the typical fall pollen of the American hay fever, rag weed, for all cases of that season, later workers, using the skin reaction, go to the extreme of injecting the patient with each and every pollen to which his skin reacts. Oppenheimer and Gottlieb carry this individualization to the point of attempting to discriminate by the skin test the patient's varying resistance to his different pollens at each treatment. This resistance may rise for some and fall for other pollens so that six or eight different pollens in different doses must be injected separately at each treatment. This is individualizing the case with a vengeance and requires an expenditure of time and skill (I almost said skin) that must be rather expensive for the patient.