The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1

dc.contributor.advisorRavenscroft, Neilen_ZA
dc.contributor.advisorWilson, Seanetteen_ZA
dc.contributor.authorEdmonds-Smith, Cesarinaen_ZA
dc.date.accessioned2014-08-13T14:26:11Z
dc.date.available2014-08-13T14:26:11Z
dc.date.issued2013en_ZA
dc.descriptionIncludes abstract.en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractPneumonia is the leading cause of death in children worldwide and is estimated to kill 1.6 million children every year. Pneumonia affects children and families everywhere, but is most prevalent in sub–Saharan Africa and South–east Asia. Serotype 1 is responsible for up to 20 % of invasive pneumococcal diseases (IPD) in developing countries and has been the cause of several outbreaks in the African meningitis belt. Conjugate vaccines are effective in young children, induce immunological memory and reduce carriage. A conjugate vaccine against 7 serotypes (PCV7) was licensed in 2000 which resulted in a dramatic reduction of IPD. An increase in the number of cases due to non–vaccine serotypes (serotype replacement) led to the recent development and licensure of 10– and 13– valent conjugate vaccines that provide broader coverage. This thesis describes the development of purification and conjugation processes and associated analytical methods for the preparation of a Streptococcus pneumoniae serotype 1 polysaccharide (Pn1) conjugate vaccine. The Pn1 polysaccharide was purified following a two–step process utilising a differential filtration with ethanol. Analytical tests including size analysis, uronic acid composition, O–acetylation and purity (nucleic acids and protein) were optimized and performed on Pn 1 lots. The purified polysaccharide was found to meet World Health Organisation (WHO) specifications.The purified polysaccharide is viscous with a rigid structure that hampers full conjugation reactions and detailed characterisation. Size–reduction was performed and shown to have no impact on the structural integrity of the generated saccharide. The O–acetylated size–reduced polysaccharide was amenable to full nuclear magnetic resonance (NMR) characterisation to confirm the structural identity of Pn1 and determine the percentage of cell wall polysaccharide (CWPS) and the degree and position of O–acetylation present.Composition analysis was performed using published hydrolysis methods, however, they resulted in low recoveries and therefore alternative microwave assisted conditions were investigated followed by chromatographic separation and analysis. The size–reduced polysaccharide was conjugated to hydrazide–derivatized protein carriers via the polysaccharide carboxyl groups. The conjugates prepared using different activators were evaluated in mice and the immunogenicity data showed that they were non–inferior to two commercially available conjugate vaccines.en_ZA
dc.identifier.apacitationEdmonds-Smith, C. (2013). <i>The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/6304en_ZA
dc.identifier.chicagocitationEdmonds-Smith, Cesarina. <i>"The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Chemistry, 2013. http://hdl.handle.net/11427/6304en_ZA
dc.identifier.citationEdmonds-Smith, C. 2013. The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Edmonds-Smith, Cesarina AB - Pneumonia is the leading cause of death in children worldwide and is estimated to kill 1.6 million children every year. Pneumonia affects children and families everywhere, but is most prevalent in sub–Saharan Africa and South–east Asia. Serotype 1 is responsible for up to 20 % of invasive pneumococcal diseases (IPD) in developing countries and has been the cause of several outbreaks in the African meningitis belt. Conjugate vaccines are effective in young children, induce immunological memory and reduce carriage. A conjugate vaccine against 7 serotypes (PCV7) was licensed in 2000 which resulted in a dramatic reduction of IPD. An increase in the number of cases due to non–vaccine serotypes (serotype replacement) led to the recent development and licensure of 10– and 13– valent conjugate vaccines that provide broader coverage. This thesis describes the development of purification and conjugation processes and associated analytical methods for the preparation of a Streptococcus pneumoniae serotype 1 polysaccharide (Pn1) conjugate vaccine. The Pn1 polysaccharide was purified following a two–step process utilising a differential filtration with ethanol. Analytical tests including size analysis, uronic acid composition, O–acetylation and purity (nucleic acids and protein) were optimized and performed on Pn 1 lots. The purified polysaccharide was found to meet World Health Organisation (WHO) specifications.The purified polysaccharide is viscous with a rigid structure that hampers full conjugation reactions and detailed characterisation. Size–reduction was performed and shown to have no impact on the structural integrity of the generated saccharide. The O–acetylated size–reduced polysaccharide was amenable to full nuclear magnetic resonance (NMR) characterisation to confirm the structural identity of Pn1 and determine the percentage of cell wall polysaccharide (CWPS) and the degree and position of O–acetylation present.Composition analysis was performed using published hydrolysis methods, however, they resulted in low recoveries and therefore alternative microwave assisted conditions were investigated followed by chromatographic separation and analysis. The size–reduced polysaccharide was conjugated to hydrazide–derivatized protein carriers via the polysaccharide carboxyl groups. The conjugates prepared using different activators were evaluated in mice and the immunogenicity data showed that they were non–inferior to two commercially available conjugate vaccines. DA - 2013 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2013 T1 - The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1 TI - The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1 UR - http://hdl.handle.net/11427/6304 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/6304
dc.identifier.vancouvercitationEdmonds-Smith C. The development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Chemistry, 2013 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/6304en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemistryen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemistryen_ZA
dc.titleThe development of a process and quality control methods for conjugate vaccine against streptococcus pneumoniae serotype 1en_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePh Den_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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