Purification of capsular polysaccharide produced by Haemophilus influenzae type b through a simple, efficient and suitable method for scale-up

ABSTRACT

Haemophilus inXuenzae type b, an encapsulatedbacterium, causes meningitis in infants worldwide. The capsularpolysaccharide conjugated to a carrier protein is eVectivein the prevention of such infections. The traditional puriWcationprocess of polysaccharide from bacterial cultures for vaccineproduction is based on several selective precipitationswith solvents such as ethanol, phenol, and cationic detergents.The separations of solid and liquid phases are based oncontinuous centrifugation in explosion proof installations. Thelipopolysaccharides are separated by ultracentrifugation. Asimple and eYcient method that can easily be scaled-up wasdeveloped for puriWcation of polysaccharides. The ethanolprecipitation was reduced to only two steps. The phenol treatmentwas substituted by ultraWltration and enzymatic digestion.Lipopolysaccharide was removed by ultraWltrationtogether with addition of detergent and chelating agent.