Haemophilus influenzae type b conjugate vaccine stability: catalytic depolymerization of PRP in the presence of aluminum hydroxide

• Published in: Vaccine Vol. 17; no. 9; pp. 1169 - 1178
• Main Authors: Sturgess, Annie W, Rush, Kay, Charbonneau, Ronald J, Lee, James I, West, David J, Sitrin, Robert D, Hennessey, John P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05-03-1999; Elsevier
• Subjects: Adsorption; Aluminum Hydroxide - chemistry; Bacterial Outer Membrane Proteins - chemistry; Biological and medical sciences; Catalysis; Chromatography, High Pressure Liquid - methods; Fundamental and applied biological sciences. Psychology; Haemophilus influenzae; Haemophilus Vaccines - chemistry; Hepatitis B Vaccines - chemistry; Microbiology; Neisseria meningitidis; Polysaccharides - chemistry; Polysaccharides, Bacterial - chemistry; Reference Standards; Time Factors; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Conjugate - chemistry; Vaccines, Synthetic - chemistry; Virology; Pasteurellaceae; Microorganism capsule; Structure stability; Immunological adjuvant; Bacteria; Vaccine; Conjugated compound; Haemophilus influenzae; Property formulation relationship
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(98)00337-5

The structural stability of the
Haemophilus influenzae type b (Hib) capsular polysaccharide, polyribosylribitolphosphate (PRP) in an aluminum hydroxide adsorbed, polysaccharide–protein conjugate vaccine was monitored using modifications of an HPLC assay developed by Tsai et al. [Tsai C-M, Gu X-X, Byrd RA. Quantification of polysaccharide in
Haemophilus influenzae type b conjugate and polysaccharide vaccines by high-performance anion-exchange chromatography with pulsed amperometric detection. Vaccine 1993;12:700–706.]. As applied to products containing PRP conjugated to the outer membrane protein complex (OMPC) from
Neisseria meningitidis, this assay allows direct measurement of the total PRP content in very complex samples including commercial vaccine products. In addition, with the use of a high-speed centrifugation step, the assay can be used to directly quantify any PRP that is not conjugated to the OMPC carrier protein. These results provide evidence of what appears to be a catalytic reaction taking place between the phosphodiester bond of PRP and the aluminum hydroxide adjuvant that results in hydrolysis of the PRP polymer into smaller chain lengths and liberation of PRP oligomers from the conjugate particle. The reaction approaches an asymptotic limit after approximately two years at 2–8°C. Clinical studies which span this time period confirm that the modest decrease in conjugated PRP content over time does not impact the overall clinical effectiveness of PRP–OMPC-containing vaccines.