New meningococcal C polysaccharide-tetanus toxoid conjugate Physico-chemical and immunological characterization.

The polysaccharides (Ps) are thymus-independent 2 (TI-2) antigens and poor immunogens in infants and young children; as a result of this delayed response to Ps antigens during ontogeny, infants and young children are highly susceptible to infections caused by encapsulated bacteria. Meningococcal group C polysaccharide (PsC)-proteins conjugate vaccines have been reported to induce significant serum IgG antibodies and immunologic memory in infants resulting in very effective vaccines. We describe here the obtainment, by a new method, of a neoglycoconjugate intended to immunize against Neisseria meningitidis serogroup C, its characterization by physico-chemical methods, including (1)H NMR and fluorescence spectroscopy methods, as well as the characterization of the immune response induced in mice by such conjugate.

New method for obtaining conjugated vaccines.

We describe a new method to obtain conjugates against Neisseria meningitidis serogroups A, B, C, Vibrio cholera, and Salmonella typhi and their immunogenicity in Balb/c mice. The saccharides were activated by basic hydrolysis with the generation of amine groups in the saccharidic chain, and these groups were linked to carboxyl groups of tetanus toxoid by via carbodiimida-mediated reaction. The resultant conjugates were administered to mice for the immunogenicity studies.

Mucosal immune responses to meningococcal C polysaccharide-protein conjugate in mice.

Mucosal delivery of vaccines represents an attractive approach because this is a region of first contact point for inhaled antigens. We have obtained a meningococcal group C polysaccharide-tetanus toxoid conjugate (MGCP-TT) and evaluated it for intranasal route in mice. The conjugate was obtained by a developed method in our laboratory.