Western, Eastern and Venezuelan equine encephalitis viruses vary in infection rates and severity of disease, although all three pathogens are associated with risks of flu-like symptoms, potential central nervous disorders, and death. The virus is spread by mosquitos to humans and can result in the rare condition of encephalitis in about 5% of the people that become infected. In the United States, an increase in cases of Eastern equine encephalitis, known also as Triple E, has been reported over the past years, and in 2019 almost 40 cases, including 15 deaths were reported by the CDC in what is the largest ever recorded outbreak of Triple E. There are currently no approved vaccines against any of the equine encephalitis viruses.
In March 2018, Bavarian Nordic entered a multi-year contract valued at up to USD 36 million with the U.S. Government to develop MVA-BN WEV, a vaccine against all three strains of the equine encephalitis virus. Under this contract, Bavarian Nordic is conducting a Phase 1 clinical trial, which was initiated in October 2019.
The Phase 1 trial will evaluate the safety, tolerability and immunogenicity of MVA-BN WEV in 45 healthy adults in three treatment groups receiving different doses of the vaccine. Topline results from the study are expected to become available in 2020.
A successful Phase 1 trial, based on demonstrating a favorable safety and immunogenicity could lead to follow-on funding beyond the initial contract award of USD 36 million, to support further preclinical, clinical development and manufacturing to support licensure in the United States.