ABSTRACT
The potential of capsular polysaccharides as vaccines was fully confirmed when it was demonstrated unequivocally that multivalent pneumococcal polysaccharide vaccines were able to provide type-specific protection in humans against the acquisition of pneumococcal infection. This chapter focuses on glycoconjugates of the polysaccharides of bacterial pathogens for which the development of vaccines has had the highest priority. Although a degree of empiricism was used in the construction of many of the glycoconjugates vaccines, several still conform to some general guidelines, which can be formulated on the basis of the chemical and other parameters required for the design of efficacious glycoconjugate vaccines. Depolymerization of capsular polysaccharides to produce fragments has been extensively employed in the construction of glycoconjugates. Random activation of polysaccharides produces glycoconjugates which are more substantially cross-linked, and the length of polysaccharide between contiguous linkage sites cannot be measured.
