title: A novel enzyme-linked immuno-sorbent assay (ELISA) for the quantification of total and free polysaccharide in Haemophilus influenzae b-Tetanus toxoid conjugate vaccines in monovalent and combined vaccine formulations.
abstract: Current Haemophilus influenzae b conjugate vaccines (Hib), which are made of purified capsular polysaccharide (poly-ribosyl-ribitol-phosphate; PRP) conjugated to a carrier protein, are almost completely evaluated by physico-chemical methods to ensure the integrity and stability of the vaccine and consistency of manufacture of batches. The absence of a potency assay makes the quantification of total PRP content (in SI units) and of % free polysaccharide in final fills or bulk components of Hib vaccines critical release tests for both manufacturers and national control authorities. Here we describe a simple and sensitive Enzyme-Linked Immuno-sorbent Assay (ELISA) which has been developed to quantify total and free PRP content in Hib-TT vaccine alone or when in combination with other vaccines. The assay is robust, specific and highly sensitive.
authors.affiliation: Bacteriology Division, National Institute for Biological Standards and Control, MHRA, Potters Bar, Hertfordshire EN6 3QG, UK.
authors.forename: Manolya
authors.initials: M
authors.lastname: Saydam
authors.affiliation: Biostatistics Division, National Institute for Biological Standards and Control, MHRA, Potters Bar, Hertfordshire EN6 3QG, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Rigsby
authors.affiliation: Bacteriology Division, National Institute for Biological Standards and Control, MHRA, Potters Bar, Hertfordshire EN6 3QG, UK. Electronic address: Fatme.mawas@nibsc.org.
authors.forename: Fatme
authors.initials: F
authors.lastname: Mawas
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D018073:Haemophilus Vaccines / Q000737:chemistry*; D057230:Limit of Detection; D011134:Polysaccharides / Q000032:analysis*; D015203:Reproducibility of Results; D013745:Tetanus Toxoid / Q000737:chemistry*; D017778:Vaccines, Combined / Q000737:chemistry*
chemical_list: D018073:Haemophilus Vaccines; C055753:Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate; D011134:Polysaccharides; D013745:Tetanus Toxoid; D017778:Vaccines, Combined
keywords: Conjugate vaccine; ELISA; Haemophilus influenzae b; Polysaccharide