Comparison of Rabbit and Mouse Models for Persistence Analysis of Plasmid-Based Vaccines

Experiments were conducted with a cationic lipid-formulated pDNA vaccine (VCL-AB01) to evaluate the models used to determine biodistribution, persistence and the potential for integration (into genomic DNA) of plasmid DNA-based vaccines. Mice were injected with a high-dose volume of 50 μL unilaterally containing ~2.42 × 1011 plasmid copy numbers (PCN) or a low-dose volume of 20 μL bilaterally (~9.67 × 1010 PCN). Rabbits were injected bilaterally with a 0.5 mL (~1.37 × 1011 PCN) volume. Injection site muscle tissue was harvested two days, one month, and two months postinjection for the low-dose murine and rabbit models and two days and two months postinjection for the high-dose murine model. Total DNA was extracted and analyzed by real-time quantitative PCR for sequences specific to the injected pDNA. The geometric mean PCN/μg of total DNA from the high and low dose models were compared to determine if injection volume impacts clearance and/or persistence. Results from these studies showed that PC...