CONJUGATE VACCINE COMPOSED OF THE POLYSACCHARIDE MOIETY OF THE LIPOPOLYSACCHARIDE OF VIBRIO CHOLERAE 0139 BOUND TO TETANUS TOXOID

摘要

A conjugate made of the polysaccharide moiety (O-specific polysaccharide + core) of the lipopolysaccharide (LPS) of V. cholerae O139 (pmLPS) was prepared by derivatization of the pmLPS with adipic acid dihydrazide and coupling to tetanus toxoid (TT) by carbodiimide-mediated condensation. Said conjugate elicited high levels of IgG antibodies, peaking 3 months after the first immunization and declining slowly during the following 5 months. TT alone, or as a component of conjugate, induced mostly IgG antibodies. Antibodies elicited by the conjugate recognized both capsular polysaccharide (CP) and LPS from V. cholerae O139, and were vibriocidal. They were also protective in the neonatal mouse model of cholera infection. The conjugation of the O139 pmLPS, therefore, enhanced its immunogenicity and conferred T-dependent properties to this polysaccharide.