Alphaviruses

Alphaviruses are enveloped single-stranded RNA viruses that can infect a wide range of hosts, including mammals, birds, amphibians, fish, and arthropods. More than 30 alphavirus species have been identified, of which several alphaviruses such as the Chikungunya virus, Venezuelan equine encephalitis virus, Sindbis virus, and Semliki Forest virus have proven pathogenic in both domestic animals and humans. Alphaviruses have been suggested to be responsible for several epidemics in different parts of the world causing fever, joint pain, and in serious cases encephalitis with fatal outcomes. The structure of various alphaviruses has been resolved, and the viral replication has been outlined. Moreover, immune responses elicited by alphavirus infections have been studied in detail. As alphaviruses belong to self-replicating RNA viruses, efficient expression vectors have been engineered, which have provided attractive opportunities for therapeutic applications and vaccine development against infectious diseases and various cancers.