Figure 1.

Inhibition of the type 1 interferon (IFN I) response to sa-RNA using corticosteroids and other inhibitors increases production of the sa-mRNA-encoded transgene but is detrimental to the vaccine effect

The application of corticosteroids at the site of vaccine administration in mice prior to intradermal electroporation suppresses IFN I production and vaccine efficacy (top right panel) but increases expression of a luciferase reporter coexpressed from the sa-mRNA (bottom right panel). Modification of the saRNA purification protocol to eliminate most of the dsRNA led to reduced activation of innate immunity but increased vaccine efficacy against Zika virus (bottom left panel).