Among the alphaviruses pathogenic to humans, chikungunya virus (CHIKV) causes explosive outbreaks that can have a dramatic impact on the affected communities. While CHIKV outbreaks have been documented for the past 50 years, the magnitude of these recent outbreaks has led to the speculation that the virus is emerging with new patterns of virulence and transmission. Traditionally, CHIKV disease is a debilitating and prolonged arthralgic syndrome that primarily affects the peripheral small joints. While the acute febrile phase of the illness normally resolves within a few days, the pain associated with CHIKV infection of the joints persists for weeks or months causing serious economic and social impact on both the individual and the affected communities. However, during the 2005–2007 ongoing explosive epidemics, anecdotal cases of CHIKV-associated deaths, encephalitis, and neonatal infections have been reported. Despite these facts, there are no therapeutics or vaccines commercially available for the virus. Preliminary vaccine development and characterization has been initiated for CHIKV leading to Phase 2 human clinical trials. Results from these studies have been promising to date. As epidemics of illness caused by both CHIKV continue to occur with greater intensity and frequency, the possibility of producing a vaccine for widespread distribution may also be more likely. By understanding the biology, ecology, and epidemiology of this virus, we can provide a framework from which to propose and support alphavirus vaccine development.
