Alphavirus

 Alphaviruses are composed of two different subclasses, Old World and New World viruses. Old World species include arthritogenic viruses such as chikungunya (CHIKV) and Ross River virus that cause inflammatory joint disease in humans. In contrast, Western, Eastern, and Venezuelan equine encephalitis viruses (WEEV, EEEV, and VEEV, respectively) are among the New World viruses that cause fatal encephalitis. The structural envelope (E) glycoprotein (E3, E2 and E1 with 6K) is the target for vaccine development or treatment.