Symptoms. — When a small quantity of active vaccine- or cow-pox virus is brought in contact with the cutis vera of an unprotected person by removing a portion of the cuticle, as in the familiar process of vaccination, no appreciable effect is produced until the end of the fourth day. Then, at the point of in troduction, will appear a small, hard, elevated papule with a minute vesicle on its apex, very closely resembling the individual papules of variola. The pap ule continues to enlarge in all directions for four days, the vesicle becoming first flattened, then indented in its centre, and filled with transparent lymph or virus. During the fifth day tion commences, indicated by an areola of redness, swelling, and a slightly bid appearance of the lymph in the vesicle. The swelling and redness around the pustule continue to increase for three or four days, accompanied by slight symptoms of general fever, when a dark-brown spot appears in the centre of the pustule now fully distended with purulent fluid. From this time all feelings of general fever disappear, the areola of redness and swelling ishes, and the dry, brown spot increases until the pustule has become replaced by a thick, brown scab, under which cicatrizatiou takes place and the scab falls off, leaving an indented or pitted cicatrix, or scar.
The process of desiccation usually oc cupies from seven to nine days, making the whole time from the introduction of the virus to the complete cicatrization of the pustule about three weeks. As a rule, in vaccination, papules appear only at the points where the virus has been introduced; but in a very small percent age of cases a few papules have appeared on other parts of the surface. In no case is there developed in the system a contagium sufficient to render the ease contagious or communicable from person to person in any other way than by vaccinating with the virus.
Vaccination-rashes may be divided into two main groups, the first being those that arise from pure vaccine-inoculation. There may be secondary local inoculation of vaccine-eruptions that occur before vesicles form, and eruptions after the formation of vesicles, as well as sequels; of various forms due to the irritation of vaccination, and usually occurring in pre disposed subjects. The second group in cludes eruptions due to some admixture with the vaccine-virus, which may be in the virus at the time of vaccination, cousing some local disease, such as impetigo contagiosa, or constitu tional disease, such as syphilis, leprosy, or tuberculosis; or these may be intro duced after the vesicles have developed and ruptured and then cause conditions like erysipelas, celhditis, gangrene, or In the first group, among erup tions occurring before vesicles form, may he noted vesicular and bullous eruptions and erythema mnitiforme.
In the next subsection of this group may be noted the frequency of roseola and a measles-like rash and a lichen of various forms that comes out in suc cessive crops. Purpuric rashes may oc
cur in very cachectic children. Eczema may occur, but it should not be attrib uted to the vaccination sinless it appears before this is completely healed. Psoria sis after vaccination is a pure curiosity. The irritation of vaccination is likely to determine the outbreak of the rash of congenital syphilis, and it is absolutely wrong to consider a syphilitic rash clue to inoculation at the same time with the vaccine, unless the rash appears only about fifty days subsequent to the in oculation. Tuberculosis has been intro duced with vaccine-virus, but this is ex tremely rare, and cannot occur when glycerinated calf-lymph is used. Robert J. Carter (Lancet, Aug. 20, '981.
Tetanus is not a frequent complication of vaccination, a total of 95 cases hay ing been collected. The number of cases recently observed is out of all propor tion to what has been observed hereto fore. The cases arc chiefly American and occur scattered throughout the eastern United States and Canada. They have nothing, to do with atmos pheric, telluric, or seasonal conditions. They occur in small numbers after the use of various viruses. An overwhelm ing proportion has occurred after the use of a particular virus. The tetanus organism may he present in the virus in small munbers, being derived from the manure and hay. Occasionally the num ber of bacilli becomes greater than usual through carelessness or accident. The future avoidance of the complication is to be sought for in greater care in the preparation of the vaccine-virus. The writer himself contends that vaccination should be carefully done with aseptic precautions; that the after-treatment, of the site of the scarification is very im portant in preventing cellulitis, erysipe las, and tetanus; that vaccination, when carefully done with properly prepared lymph, is a harmless procedure. J. H. .1cCollom (Boston Med. and Surg. Jour., Aug. 21, 1902).
Diagnosis.—The diagnostic features of the true vaccine-sore are seen in its exact similarity to the distinct or separate sore of unmodified variola. It passes through the same stages, in the same order, and in about the same time, but attains a larger size.
Etiology.—The cause or causes capa ble of producing the original cow-pox as a bovine disease are not known with certainty. The close similarity of the sores of cow-pox and variola and the power of the virus of those of the former to render the human subject immune to the contagium of the latter caused many members of the profession to regard the disease in the cow as produced by the variola contagium which in passing through the cow was so modified as to lose its virulence while retaining its im munizing power.