Spotted Fever Immunization: Results and Recommendations*

CONSEQUENT upon a widen-ing area of distribution and upon the increasing population within the areas that have become endemically affected, the spotted fever of the Rocky Mountains has become of enhancing importance as a public health problem.218*223 Of this fact, cognisance has been taken by state and local health officers, by regional and inter-state conferences, by private practitioners, and by the increasing co-operation of the Federal Government. The cooperation of the latter has taken the form chiefly of conducting epidemi-ologic and ecologic studies in the field, of carrying out laboratory investiga-tions on the virus, and of the manu-facture, in annually increasing quanti-ties, of a preventive vaccine of proven, and we might add, great value.209'225 The vaccine, as originated by R. R. Spencer and R. R. Parker has an im-portant place in any control program, but is particularly necessary for use in localities where tick control measures can not be conducted economically, due either to the character of the terrain, the sparseness of the popula-tion, or the very occasional character of the menace from spotted fever. Where, however, it has been found profitable to maintain tick control pro-cedures, there is not yet justification for diminishing the tick control activities because of the recent intro-duction of a preventive vaccine.224 This paper will be limited to a study of the production, distribution, and ef-ficacy of the spotted fever vaccine as originated by R. R. Spencer and R. R. Parker; the value of the vaccine as compared with other spotted fever con-trol measures being given only incident-al consideration inasmuch as this aspect has lately been elsewhere considered in detail by the author.231 The need for a preventive serum or vaccine was early apparent in the study of possible prophylactic measures against spotted fever, as the disease is of great economic importance in the areas where it is most prevalent; as also in areas where it is of (consistent-ly) great virulence.36'47'97 P. G. Heine-mann and J. J. Moore76'84 attacked the problem from the aspect of passive im-munity. They showed that passive immunization offered virtually no pros-pect for effective prevention or ther-apy. It was H. T. Ricketts49'56'76 and associates61'69, and later Noguchi142'143