Live Attenuated Vaccine to Prevent Disease Caused by West Nile Virus

West Nile virus (WNV) has recently emerged in the U.S. and is considered a significant emerging disease that has embedded itself over a considerable region of the U.S. WNV infections have been recorded in humans as well as in different animals. From 1999-2014, WNV killed 1,765 people in the U.S. and caused severe disease in more than 41,762 others. This project is part of NIAID's comprehensive emerging infectious disease program.

The methods and compositions of this invention provide a means for prevention of WNV infection by immunization with attenuated, immunogenic viral vaccines against WNV. The invention involves a chimeric virus form comprising parts of WNV and Dengue virus. Construction of the hybrids and their properties are described in detail in multiple publications. The WNV chimeric vaccine does not target the central nervous system, which would be the case in an infection with wild type WNV. Importantly, two successful Phase I clinical trials were recently carried out with the vaccine. The live attenuated WNV vaccine is safe, well-tolerated, and immunogenic in healthy adult volunteers. Furthermore, the vaccine virus may also be considered for use as a safe reagent handled at bio-safety level 2 facilities for WNV diagnosis and surveillance.