Infections with Zika virus are strongly associated with complications such as congenital microcephaly and can trigger Guillain-Barré syndrome in humans, highlighting the urgent need for a safe, efficacious vaccine as a preventative countermeasure. In a recent paper published in Cell, Richner et al. generated a lipid nanoparticle encapsulated modified mRNA vaccine encoding the prM and E genes from Zika virus, which showed protection and sterilizing immunity in immunocompetent mice.