Fig. 3. DIP vaccination confers durable protection.
Mice were intraperitoneally vaccinated with 105 PFU DIP and challenged intranasally with 5 × 103 PFU WT virus at 1 (a–c) or 6 (d) mo post-vaccination. Latent infection in the spleen was examined at 14 (a, b) or 28 (c, d) d after challenge. Viral loads were determined by infectious center assay (a, c, d) and qPCR (b). Dotted line indicates detection limit. The graph depicts the pooled data from 2 independent experiments using different numbers of mice for each replicate. Data for individual mice, means, and SD indicated by error bars were plotted. Statistical significance was analyzed by a two-tailed Student’s t-test. P < 0.05*, P < 0.01**, P < 0.001***, and P < 0.0001****.