The Bactericidal Actions of O and VI Antibodies against Salmonella Typhosa

Abstract
Anti-Vi and anti-O are both bactericidal against virulent strains of S. typhosa. With currently used vaccines, however, the anti-Vi response contributed very little to the bactericidal action of immune serums. The bactericidal activity of such serums reflected primarily their anti-O content. The apparent lack of protection afforded by anti-Vi in human subjects may be related to this finding.