Chikungunya virus was first isolated from the blood of a febrile patient in Tanzania in 1953, and has since been cited as the cause of numerous human epidemics in many areas of Africa and Asia and most recently in limited areas of Europe. Chikungunya virus is a member of the genus Alpha virus, in the family Togaviridae. Chikungunya fever is diagnosed based on symptoms, physical findings (e.g., joint swelling), laboratory testing, and the possibility of exposure to infected mosquitoes. There is no specific treatment for Chikungunya fever; care is based on symptoms. PBMC isolated from a Chikungunya infected patient was cultured in the CD40 system supplemented with an EBV viral suspension. Immortalized antibody-secreting B clones were obtained and screened for their neutralizing activity against several Chikungunya virus strains. Seroneutralization of other viruses such as Ross River virus and ONyong Nyong virus was found.