Figure 1. Viral RNA detection in RVFV DDVax, MP-12 and ZH501in vitro challenged mosquito bodies, legs/wings and salivary expectorants at 14 dpi. Sample positivity rates are listed in S1 Table. Viral copy number was calculated using a standard curve of diluted L segment transcripts amplified from a plasmid. Profiles from 3 biological replicates were combined, with approximately 40 mosquitoes per replicate.
Ae. aegypti from the in vitro virus exposure experiments also showed significantly reduced dissemination in DDVax-infected mosquitoes compared to those challenged with MP-12 or ZH501, respectively (χ2 test, vs MP-12 p = 0.02, vs ZH501 p = 2.2e-16), as indicated by the presence of viral RNA in legs/wings (Figure 1B). Aedes aegypti mosquitoes exposed to DDVax had no evidence of infectious virus in expectorated saliva, whereas 16% and 27% of saliva samples were CPE-positive in MP-12 and ZH501 infected mosquitoes, respectively (Table 2, χ2 test, vs MP-12p = 2.2e-16, vs ZH501 2.821e-09).