Cell-bound haemagglutinin (CHA) of V. cholerae 01 as protective antigen.

The study of immunogenicity of cell-bound haemagglutinin (CHA) of Vibrio cholerae E1 Tor in mice revealed that the CHA was a good antigen when it was adsorbed onto the surface of sheep red blood cells and given orally to mice. The antigen not only induced high levels of various class antibodies which sustained in the intestinal tracts for a long period of time (longer than 6 months) but also the antibodies were protective against homologous cholera challenge. The degree of protection seems to correlate with the level of IgA in the intestinal washing. The protective ability was conferred mainly by anti-CHA.