Zika virus protection by a single low-dose nucleoside-modified mRNA vaccination.

Zika virus (ZIKV) has recently emerged as a pandemic associated with severe neuropathology in newborns and adults. There are no ZIKV-specific treatments or preventatives. Therefore, the development of a safe and effective vaccine is a high priority. Messenger RNA (mRNA) has emerged as a versatile and highly effective platform to deliver vaccine antigens and therapeutic proteins. Here we demonstrate that a single low-dose intradermal immunization with lipid-nanoparticle-encapsulated nucleoside-modified mRNA (mRNA-LNP) encoding the pre-membrane and envelope glycoproteins of a strain from the ZIKV outbreak in 2013 elicited potent and durable neutralizing antibody responses in mice and non-human primates. Immunization with 30 μg of nucleoside-modified ZIKV mRNA-LNP protected mice against ZIKV challenges at 2 weeks or 5 months after vaccination, and a single dose of 50 μg was sufficient to protect non-human primates against a challenge at 5 weeks after vaccination. These data demonstrate that nucleoside-modified mRNA-LNP elicits rapid and durable protective immunity and therefore represents a new and promising vaccine candidate for the global fight against ZIKV.