Intralymphatic immunization: current status.

-A progress report and the research plan for a new method of antitumor immunization using the intralymphatic route are presented. A total of 205 intralymphatic infusions of intact cellular vaccines have been performed in normal and tumorbearing dogs. In vitro and in vivo experiments on normal dogs demonstrated that intralymphatic immunization produces a more rapid and more intense qytotoxic cellular immune response compared to the subcutaneous route. ExI~eriments in tumor-bearing dogs showed reduction or stabilization of tumor mass after intralymphatic infusion of irradiated malignant cells. These data indicate that intralymphatic immunization may be the method of choice for stimulating strong cellular immune responses to weakly immunogenic materials.