Immunization strategies to prevent Zika viral congenital eye and brain disease

Zika virus (ZIKV) is an important human pathogen, which causes developmental abnormalities in affected children. We have developed series of Zika viral vaccine candidates and evaluated their replication and toxicity profiles in iPSC-derived ocular progenitor cells. The Zika viral vaccine candidates meeting growth attenuation criteria in cell culture were selected for animal safety and efficacy preclinical studies. We observed that an attenuated vaccine candidate, VAX2B, exhibited strong immunogenity and safety profiles in adult mice. The safety profile of VAX2B requires further improvement in the neonatal mice. We are currently investigating the safety and efficacy characteristics of additional ZIKV vaccine candidates. 

We proposed to develop vaccine product to prevent Zika virus infection. A recombinant Zika vaccine vector was engineered to induce anti-ZIKV immunity and to inhibit ZIKV infection in pregnant animal. Mice model was used for evaluating safety and efficacy. We have observed that ZIKV vaccinated pregnant mice had 100% protection from wild type Zika virus challenge and had significantly higher levels of cell mediated immune response than unvaccinated challenged mice. Based on body conditional score vaccinated pregnant mice stayed healthy even after wild type ZIKV challenge. Vaccinated mice were borne healthy pups with normal behavior and eye sight. This CIRM funded study demonstrated the successful development of safe and effective vaccine candidate targeting Zika viral disease.