This invention addresses how to rapidly prevent alphavirus-induced encephalitides before and after exposure to alphaviruses. The invention discloses a single dose administration of two types of recombinant viral vectors: one expressing interferon and another expressing the structural proteins of alphaviruses or a single dose administration of the recombinant viral vector co-expressing both interferon and the structural proteins of alphaviruses. This invention can be used to prevent humans from alphvirus-induced encephalitides in the event of a bioterrorism attack or biowarfare in which alphaviruses such as Venezuelan (VEEV), eastern (EEEV) and western (WEEV) equine encephalitis viruses are deliberately released to humans, a natural outbreak of alphaviruses, and an accidental exposure to alphaviruses in laboratory.
