The importance of the Vi antigen

Abstract

The characteristics of the Vi antigen present in typhoid bacilli and other Salmonellae was discussed. Vi agglutination experiments failed to produce better results than other diagnostic means. Inoculation with Vi vaccines increased mouse protecting antibodies to a fairly high level. Experiments were carried out in vitro and in mice which showed that typhoid and paratyphoid C bacilli with Vi antigen show a stronger initial multiplication than organisms without the Vi factor. The importance of these findings is discussed.