Bovine vaccinia or cowpox never occurs spontaneously in a human subject but is artificially produced in man by inoculation with a lymph originally derived from the cow. This operation is termed vaccination and is characterized by one or more skin lesions depending upon the number of points inoculated by the special virus. A typical and so-called successful vaccination will present consecutive stages of papules, vesicles, pustules and desiccation, ending in the falling of the crusts at the end of the third week and permanent scarring which eventually becomes white with minute pits or depressions. Constitutional disturbances, including fever to a varying degree, are often present. When this process is complete, total or partial immunity against smallpox is conferred upon the person vaccinated.
The actual operation of vaccination is so well understood that it would be useless to go into details, except to remark that a perfect result, including the avoidance of complications or sequelae can only be achieved by exercising care as to the preparation of the vaccine, asepsis during the actual operation of vaccination, and subsequent protection. Furthermore, the general condition of the individual should be as nearly normal as possible. The protective value afforded by vaccination far outweighs any disease-protective value afforded by vaccination far outweighs any disease-producing effects it may possess. These latter are so many and so diversified that it is necessary to suggest a divisional grouping more or less arbitrary and for that purpose the classification of Malcolm Morris as enlarged and modified by Louis Frank, is the best. This, with some changes of may own, is as follows:
1. Eruptions due to Local. Erythema.
vaccine virus, Dermaritis.
2. Eruptions due to Local. Cellulitis.
mixed inoculation Erysipelas.
introduced at time of Gangrene.
vaccination of subsequently Tuberculosis cutis.
Gangrene, Systemic. Pyemia.
3. Eruptions following vaccination. Pemphigus.
Any physician whose experience covers a few hundred vaccinations, will recall some of the above types of vaccinal eruptions. Erysipelas and generalized vaccinia are uncommon. Cellulitis, gangrene and septicemia are rare, while syphilis, leprosy and tuberculosis are only possible results from infective inoculation. The sequelae of vaccinia, as noted under group three of the above scheme, can probably be greatly extended but it is not our purpose to mention every possible condition. In these days of improved technic, when bovine virus is used almost exclusively, most of the eruptions are readily preventable, and even when they do occur, are usually of a temporary erythematous or urticarial variety.
Local treatment aims to relieve the subjective sensations and to protect the lesions. Occasionally antiseptic methods are necessary. If so, they are the same as outlined for dermatitis venenata and acute eczema.