Equine encephalitis
MVA-BN® WEV
- MVA-BN® WEV has completed Phase 1 clinical development demonstrating potential for broad, and long-term protection
- Phase 2 planned for 2025
MVA-BN WEV is a multi-valent vaccine candidate in development against western, eastern and Venezuelan equine encephalitis viruses, which are rare, but potentially deadly viruses transmitted to humans by mosquitos. The development is fully-funded under contracts with the US government.
Preclinical studies of MVA-BN WEV have demonstrated protective efficacy and results from a Phase 1 first-in-human trial showed that the vaccine was well tolerated and immunogenic across all dose groups. Neutralizing antibody responses were observed against Venezuelan equine encephalitis virus in all dose groups, with peak levels reached after the second vaccination. Recent data has confirmed neutralizing antibody responses also against western and eastern equine encephalitis viruses that were durable throughout the six-months follow up period.
A Phase 2 dose-finding study is planned for initiation in 2025.
Western, Eastern and Venezuelan equine encephalitis viruses belong to the family alphavirus, and are transmitted through mosquitos, as well as birds and some mammals. While the viruses vary in infection rates and severity of disease, all three pathogens are associated with risks of flu-like symptoms, potential central nervous disorders, and death. All three viruses are considered as potential biological threats, having been investigated as potential biological weapons at various times in the past century. The viruses belong to the U.S. list of prioritized pathogens amongst other agents, like smallpox, anthrax and other lethal diseases, which are covered by the current vaccination policy for U.S. military personnel being deployed around the globe. However, there are currently no approved vaccines for human use against any of the equine encephalitis viruses.
Occasional outbreaks of eastern equine encephalitis occur in the U.S., particularly in the southern and northeastern parts of the country. According to the U.S Centers for Disease Control and Prevention (CDC), more than 10 human cases were reported annually on average over the past decade. Approximately 30% of people who develop severe eastern equine encephalitis die, and many survivors have ongoing neurologic problems1
1 https://www.cdc.gov/eastern-equine-encephalitis/about/index.html