Mosquito RNA vaccine (MORV) to block arbovirus transmission

Blood-feeding mosquitoes spread multiple viruses threatening human health and for which vaccination is unsafe or inefficient. Current control strategies focus on preventing mosquito bites, however, these involve using harmful chemicals or other costly and time-consuming measures. Here, we create a mosquito RNA vaccine (MORV) to reduce spread of two harmful mosquito-borne flaviviruses: West Nile virus (WNV) and Zika virus (ZIKV). The MORV has a design based on naturally occurringnarnaviruses. A first narnavirus (CxNV1) was found in Culex tarsalis cell culture and here a second narnavirus (AejapNV1) from Aedes japonicus is described. Both narnaviruses initiate a highly active RNA interference (RNAi) response in their mosquito host. The MORV is designed to contain a WNV or ZIKV fragment in the narnavirus sequence without disturbing the natural mbigrammatic structure of the narnavirus. Current experiments involve testing if the inserted fragments can trigger an RNAi response that could protect against WNV or ZIKV infection. Since narnaviruses have small genomes and persistently infect mosquitoes, the MORV has the potential to be maintained in mosquito populations. Releasing MORV vaccinated mosquitoes may help reduce flavivirus transmission in the field.