A Chick Embryo-Derived Complement-Fixing Antigen for Western Equine Encephalomyelitis

Abstract
Summary A complement-fixing antigen of the WEE virus is described. The antigen is prepared from the fluids and membranes of the infected chick embryo and has a high degree of sensitivity. Since complement-fixing antibody in human WEE virus infections is slower in appearing than the neutralizing antibody, diagnosis can usually be made by the complement fixation method whereas diagnos-tically significant rises in antibody frequently are not demonstrable by the neutralization test.