A Novel Replication-Competent Vaccinia Vector MVTT Is Superior to MVA for Inducing High Levels of Neutralizing Antibody via Mucosal Vaccination
Figure 5
Influence of pre–VTT vaccination on the efficacy of MVTT-S or MVA-S via the same i.n. or i.o. route of immunization, respectively.
Groups of 4 mice were inoculated with 106 PFU VTT via i.n. or i.o. route, and were subsequently (six months later) injected with 2×106 PFU MVTT-S or MVA-S twice at one month interval via the same routes. No anti-S Nab responses were detected in these animals (flat lines on the X axis). In contrast, placebo mice, that were previously given PBS, developed significant levels of anti-S Nab responses after received two MVTT-S (solid symbol) or MVA-S (empty symbol) injections via the same i.n. or i.o. route. The Y axis stands for the percentage of inhibition whereas the X axis represents the serum dilution factor. The dash line indicates the level of 50% of viral inhibition. The experiment was repeated twice with similar results obtained.