Definition.—An infectious, eruptive disease which appears upon the teats or udder of the cow in the form of small papules, which soon become vesicles, the virus of which, introduced into the human body by vaccination or otherwise, results in a systemic disturbance, the effect of which is to effect immunity, more or less permanent, against small-pox, the local lesion being followed by the well-known pit or scar.
The virus—vaccine—is obtained either directly from the calf, bovine lymph, or from a healthy person, preferably a child who has been recently vaccinated, human lymph.
History.—There is no more interesting chapter in medical literature than the discovery of vaccination by Jenner, and he is justly entitled to rank as one of the greatest benefactors of mankind. Although not the first to practice vaccination, he is justly entitled to all honor, for he conceived the idea of its great value, and pursued the subject until it passed from the realm of speculation to that of an assured fact.
As early as 1774 Jesty, a Dorsetshire farmer, who had had cow-pox, vaccinated his wife and two sons, then went to London and presented himself and family to the inoculation hospital and defied them to give him or his family small-pox; but the hospital physicians failed to appreciate the fact that a great discovery had literally been thrust upon them, and it remained for Jenner, after twenty years of study and observation, to prove to the world that the belief in cow-pox as a preventive to small-pox, was not a dream, but as certain in its effects and as easily proven, as a problem in Euclid.
While a student at Sudberry he early heard of the popular belief which prevailed in the dairy districts, that any one having-had cow-pox could not take small-pox, and when one day he was consulted by a young- woman and the subject of her taking smallpox was mentioned, she said, "O, I can't take that disease, for I have had cow-pox," there took root in his fertile brain an idea that was to grow and develop until it should bring forth fruit that would gladden the hearts of mankind throughout the world.
Mentioning his views to the celebrated Dr. Hunter, he was told not only to think but to act, to prove his thoughts correct, and, with a patience and perseverance born of genius, he pursued his studies for over twenty years till they thoroughly satisfied him of the truth of his discovery. He published, in 1798, "An Inquiry into the Causes and Effects of Variola Vaccinia."
At last, after years of thought, the crucial test was made, and on the 14th of May, 1796, '"he took matter from the vesicle of one Sarah Nelmes, who was suffering from cow-pox, and inoculated a boy by the name of James Phipps, aged eight years."' The cow-pox ran its natural course, and when a little over six weeks had elapsed he was inoculated on July 1st with the virus taken from a small-pox pustule, and was rewarded by finding that, as he had predicted, the boy was proof against small-pox.
For two years cow-pox disappeared, and his labors were suspended before he could give further proof of its prophylactic power, at which time he published to the world the result of his investigations.
Was it hailed with acclamations of great joy and its author proclaimed a benefactor? Not so. His fate at first was like that of nearly all great benefactors; viz., persecution and obloquy. Even the profession rejected his views; but this could not long prevail, for proof was at hand, and in less than a year after his first announcement "several of the most distinguished physicians of London signed a declaration of their confidence in it."
From this time the spread of vaccination was marvelous. It was introduced into the United States in July, 1800, by Benjamin Waterhouse, Professor of Physics at Harvard, who vaccinated his seven children. In 1801 it was practiced in France. "In 1803 the court of Spain sent out an expedition for the purpose of carrying vaccination to all the Spanish possessions in the Old and New World." It returned in three years, having made a circuit of the globe.
All nations hailed the discovery with joy and gladness. "In Russia, the emperor gave the name of Vaccinoff to the first child vaccinated, and made its education a public charge;" while in Germany the day of Jenner's birth and the date of his first vaccination were made feast days. Foreign courts vied with each other in bestowing honors upon Jenner. He was voted honorary membership in many learned societies, but what was more substantial was the appropriation by Parliament, in 1802, of fifty thousand dollars, and five years later one hundred thousand dollars more.
Nature of Vaccine.—The true nature of cow-pox is still unsettled. Some hold to the theory that it is small-pox modified by its passing through the cow, and numberless experiments have been made by inoculating cows with small-pox virus, the result being small-pox, and virus from the vesicles thus produced introduced into a child gave the same results as from original virus. Recent experiments by Celli, Babcock, and others, seemingly prove that genuine vaccinia may be produced by inoculating a heifer with variolous virus; on the other hand, French writers are equally positive that there is no relation existing between cow-pox and small-pox.
Browardel, in the "Twentieth Century Practice of Medicine," says, "The question is to-day settled, and settled by experiment." Chauveau, of Lyons, and some of his colleagues of the Lyons Medical Society, instituted some experiments which appear to us to leave absolutely no doubt as to the non-identity of variola and vaccinia. The experiments were as follows:
"In the first series, thirty beasts were selected without distinction of sex or age, and were inoculated with animal vaccine, cow-pox furnished by Lanoix, of Paris, and Pallasciano, of Naples. In all of them, without exception, a beautiful eruption was obtained. In all of these cases the eruption remained strictly localized.
"In a second series, about twenty animals were inoculated with humanized vaccine. The success was almost as complete as in the first series. These two series of experiments gave perfectly satisfactory, distinct, and unmistakable results, and proved clearly the identity of cow-pox and of vaccinia cultivated in the human species.
"Let us now see whether inoculations with true small-pox virus gave the same results. Seventeen young animals, heifers and bullocks, companions of the preceding, were inoculated with the virus of small-pox. The inoculations were made with the greatest care, but none of the animals acquired cow-pox. The inoculations were not absolutely without effect, for in every case there was a formation of very small reddish papules, which disappeared rapidly by a sort of absorption, without leaving any scab. We may conclude from this that vaccine virus and that of small-pox do not give identical results.
"But what was the papular eruption determined by the inoculation of variola? Was there anything specific about it, or was it simply the result of inflammation caused by the puncture? Fifteen of these seventeen animals were also vaccinated, ten with the virus of genuine cow-pox, and five with humanized virus. Of these fifteen animals, only one showed a typical cow-pox eruption. Here was a new fact of capital importance, for it proved that the papules produced in the bovine species by variolous inoculation constituted a specific eruption, and that this eruption was related to cow-pox just as vaccinia and variola in man; that is to say, variola protects the bovine race from cow-pox just as vaccinia protects the human race from small-pox. Was this variolous eruption in the cow purely and simply smallpox? In order to determine this, a non-vaccinated child was inoculated with the serous fluid obtained from these variolous papules, and the result was a generalized, confluent small-pox. A second child was inoculated with virus taken from the primary pustule in the first child, and it had a discrete but perfectly characteristic small-pox, but it was the papular eruption of bovine variola. We may conclude, therefore, that small-pox may be transmitted by inoculation to the cow, but it was not transformed into vaccinia in this animal's organism; it remains variola, and requires the characteristics of variola when implanted again in the human species."
This lengthy quotation, which shows the most recent views on this most important subject, makes clear to us that, despite the evident relation between variola in the human and the bovine races, these two affections are nevertheless perfectly distinct and independent, one of the other, in their essence and can not be transformed one into the other.
Vaccine Virus.—The virus consists either of the lymph taken from the vesicle, or of the scab or crust resulting from the desiccation of the pustule. Of the latter but little is used. There is an idea prevalent in the minds of the laity that disorders of various kinds, such as tuberculosis, syphilis, leprosy, and, in fact, bad blood in general, may be transmitted by means of vaccination, and, although this is possible, it has been greatly exaggerated.
Ever since Dr. Robert Cory, chief vaccinator to the National Vaccine Establishment, England, succeeded, after repeatedly vaccinating himself with virus taken from actively syphilitic children, in contracting syphilis, all doubt that it can be transmitted has been removed; and if this is the case with syphilis, then it may be true for any other disease.
For this reason, the profession has almost entirely abandoned the use of the human virus. A number of vaccine farms have been established in the United States, and the scrupulous care with which everything is conducted reduces the danger to the minimum. After removing the contents of the vesicle with great care, ivory points are dipped in the virus, and when dry are ready for use. These points soon lose their vitality, in from ten days to two weeks, and should be replaced by fresh points. Glycerinized vaccine is now largely used. This is usually served in capillary glass tubes sealed at each end. The ivory points protected by paraffin, if kept in a cool place, retain their prophylactic power longer than the unprotected.
Vaccination.—Although a very simple operation, there is often a failure in its successful performance. If good virus is used, the percentage of failures should be very small indeed. The exposed surface should be carefully abraded, care being taken not to produce hemorrhage, and at the same time sufficient abrasion to cause an exudation of lymph. The point selected is usually the insertion of the deltoid muscle, or, if a girl, it may be in the calf of the leg.
After wiping a space the size of a silver dollar with alcohol, to insure a perfectly aseptic surface, we take either a dull knife or the vaccine ivory point and make a series of scratches, crossing and recrossing each other till the lymph oozes through; then, having moistened the virus with sterilized water, it is carefully wiped upon the surface and gently rubbed until thoroughly incorporated with the lymph. After the lymph and virus have become perfectly dry, a piece of lintine secured by adhesive stripes or a light bandage completes the operation.
Formation of Vesicle.—From the third to the sixth day after vaccination, a small red spot appears at the seat of injury, which gradually increases in size, becomes swollen and indurated, forming the base of the vesicle. This is at first circular in form and filled with a transparent, limpid fluid. The vesicle is usually three or four days in reaching .maturity, when it shows the circumference hard and elevated, the center being depressed, and has a pearly gray color. The vesicle is now surrounded by a hard, inflamed surface extending for a half inch to an inch and a half in circumference, and is hot, red, and painful, and frequently the axillary glands become large and tender; or if the vaccination is on the leg, the inguinal glands become involved. About the twelfth day of the vesicle, desiccation commences, and is completed from the fifteenth to the eighteenth day, the scab dropping off the twenty-first day. The scar left is circular in form, depressed, and made up of small pits or depressions in the skin. The rete mucosum is deprived of its coloring matter, and the scar ever remains white.
During the evolution of the vesicle there is some systemic disturbance, and in nervous children there may be quite an active fever for two or three days.
The duration of immunity can not be definitely stated; in some cases it may last a lifetime, while in others it lasts but a few years, when it is said to "run out." To secure safety it is well to be revaccinated every eight or ten years, or earlier if an epidemic of small-pox makes its appearance.
Spurious Vaccination.—We occasionally meet with cases where the vesicle develops quite rapidly, is irregular in outline, and the pustule develops early, the vesicle is filled with pus and blood, is not depressed in the center, and it dips down into the cellular tissues, resulting in a true cellulitis. Deep ulcers form, and there is serious systemic disturbance. This, of course, is not protective, no immunity following.
The most common cause is the use of old virus. In children who are debilitated and sickly, especial care must be taken, not only that good virus is secured, but that the arm is perfectly aseptic and kept so during the entire evolution of the vesicle.
With the use of fresh bovine virus from a reputable firm, there is but a minimum of danger, and the patient is perfectly safe from contracting any of the horrible diseases at one time supposed to come from vaccination.
Value of Vaccination.—One has but to compare the history of small-pox before 1796 and that which has prevailed since its universal adoption, to be convinced that small-pox has largely lost its destructive power.
While vaccination is not invariably a preventive, nor always a permanent protection, yet in the very great majority of cases its protective property is of incalculable benefit. Isolation and improved sanitation can not account for the changed conditions, although due credit must be given them.
Modern small-pox has been shorn of its terrors through vaccination, most cases assuming the discrete form or appearing as varioloid, while the mortality has been reduced from thirty to forty per cent to six or eight per cent.