Single-dose vaccine for Zika without enhancement of dengue

A single-dose circular RNA (circRNA) vaccine encoding both Zika proteins NS1 and the EDIII subunit of the viral envelope protein could help protect against Zika virus without inducing antibody-dependent enhancement of dengue infection, a risk of other envelope-targeting Zika vaccines.

In a mouse model of passive maternal immunity, vaccination of the mother with lipid nanoparticles containing a circRNA construct — chosen for its ability to promote sustained antigen expression and to be stored at room temperature — encoding EDIII fused to an Fc domain protected all pups from mortality following Zika exposure, and decreased growth delays and neurological disorders in the pups, compared with no vaccination, which resulted in all pups dying. ...