Vaccine Advances against Venezuelan, Eastern, and Western Equine Encephalitis Viruses

Abstract

Vaccinations are a crucial intervention in combating infectious diseases. The three neurotropic Alphaviruses, Eastern (EEEV), Venezuelan (VEEV), and Western (WEEV) equine encephalitis viruses, are pathogens of interest for animal health, public health, and biological defense. In both equines and humans, these viruses can cause febrile illness that may progress to encephalitis. Currently, there are no licensed treatments or vaccines available for these viruses in humans. Experimental vaccines have shown variable efficacy and may cause severe adverse effects. Here, we outline recent strategies used to generate vaccines against EEEV, VEEV, and WEEV with an emphasis on virus-vectored and plasmid DNA delivery. Despite candidate vaccines protecting against one of the three viruses, few studies have demonstrated an effective trivalent vaccine. We evaluated the potential of published vaccines to generate cross-reactive protective responses by comparing DNA vaccine sequences to a set of EEEV, VEEV, and WEEV genomes and determining the vaccine coverages of potential epitopes. Finally, we discuss future directions in the development of vaccines to combat EEEV, VEEV, and WEEV.

Exposing cryptic epitopes on the Venezuelan equine encephalitis virus E1 glycoprotein prior to treatment with alphavirus cross-reactive monoclonal antibody allows blockage of replication early in infection

“…While relatively rare, natural human EEEV and VEEV infections still occur with high case fatality rates ( Aguilar et al, 2011 ; Lindsey et al, 2018 ). There are no approved vaccines or virus-specific treatment options available ( Stromberg et al, 2020 ). Most passive antibody approaches developed for prophylactic and therapeutic treatment to alphaviruses target highly neutralizing virus type-specific epitopes ( Burke et al, 2019 ; Hunt et al, 1991 , 2011 ; Hunt and Roehrig, 1995 ; Phillpotts, 2006 ).…”

Alphaviruses: Host pathogenesis, immune response, and vaccine & treatment updates

“…Other reviews show that self-amplifying RNA vaccines could be an effective approach [232]. Efforts towards developing vaccines against CHIKV [233–235], VEEV [236], and other encephalitic viruses [237] show promise.…”

Viral Diseases that Affect Donkeys and Mules

“…The Eastern equine encephalitis virus (EEEV), Western equine encephalitis virus (WEEV), and Venezuelan equine encephalitis virus (VEEV) are enveloped, single-stranded, positive-sense RNA viruses that belong to the genus Alphavirus in the family Togaviridae, that cause neurological disease in equids (horses, mules, donkeys and zebras) and humans [181]. The EEEV and WEEV have been reported in several countries in the Americas, while VEE seems to be limited to South and Central Americas [182,183].…”