The rpZDIII vaccine triggers vertical protection on newborn mice against zika virus infection.

Zika virus (ZIKV) infection is a significant public health concern, associated with serious complications such as Guillain-Barré syndrome and microcephaly. Although several ZIKV vaccine candidates are in various stages of development, none have yet been approved for human use. Previously, the rpZDIII ZIKV vaccine candidate was developed and shown to elicit ZIKV-neutralizing antibodies in BALB/c mice. In this study, the protective effects of rpZDIII were evaluated in newborn C57BL/6 mice born to mothers vaccinated with a three-dose regimen. The vaccine induced maternaI IgG responses that recognized the full-length E protein. Upon viral challenge, 80 % of the vaccinated newborns survived, displaying progressive weight gain and normal clinical appearance throughout the observation period. In contrast, offspring from unvaccinated mothers succumbed to infection. Furthermore, viral RNA was undetectable in the brain tissue of newborns from vaccinated mothers, whereas high viral loads were observed in unvaccinated mothers. These findings demonstrate the in vivo protective efficacy of the rpZDIII vaccine and support its continued preclinical development as a promising ZIKV vaccine candidate.