INTRACUTANEOUS VACCINES

Specific immunologic responses are presumed to be qualitatively identical after administration of any vaccine, regardless of dosage, site of injections, number of injections and interval between injections. The therapeutic failure of arbitrary doses of a proposed vaccine given under any one condition is thus taken as logical evidence of the clinical inefficiency of that vaccine under all conditions. This historical logic is challenged by the newer views in immunology.¹ Suggestive evidence in support of this challenge is reported by Julianelle of the Rockefeller Institute, New York, who has apparently demonstrated striking qualitative differences in immunologic response with different methods of administration of the same vaccine. His most suggestive differences are between intravenously and intracutaneously administered heat-killed cultures of typed pneumococci.

Rabbits injected intravenously with heat-killed pneumococci develop highly specialized, type-specific agglutinins for this particular pneumococcus strain, together with less specialized, species-specific antibodies for other strains. Julianelle was surprised to