In Vivo Evaluation of a Rationally Designed Single Injection Vaccine

Each year, 4-5 million lives are taken by diseases that can be readily prevented with standard vaccines requiring multiple injections. Current efforts to resolve this problem involve administrative programs to better distribute full-course vaccinations and initiation of long-term research programs to test novel technologies like mucosal immunization. However, recent advances in the field of controlled release technology may warrant revisiting a simpler strategy for single injection vaccination.

A recently published mathematical model has enabled (for the first time) the rational design of biodegradable controlled release vehicles that may provide precisely-timed courses of priming and boosting with a single injection. Indeed, using this model, we have fabricated a single injection vaccine (SIV) matching the dosing normally provided by two injections of ovalbumin (OVA)-alum, a common antigen-adjuvant formulation. Histology and cytometry analysis of the injection site and draining lymph nodes, respectively, demonstrate that this rationally-designed SIV formulation provides similar dosing kinetics in vivo when compared to a standard vaccine regimen. T-cell activation assays were used to demonstrate the similarity of immune responses. Successful demonstration of bioequivalence will further application of our strategy for single injection vaccination to disease-specific models.