The development and evaluation of medical countermeasures against severe acute respiratory syndrome coronavirus type 2

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dc.contributor.authorSookhoo, Jamie
dc.contributor.examiningcommitteeKobasa, Darwyn (Medical Microbiology and Infectious Diseases)
dc.contributor.examiningcommitteeAmbagala, Aruna (Medical Microbiology and Infectious Diseases)
dc.contributor.examiningcommitteeMurooka, Thomas (Immunology)
dc.contributor.examiningcommitteePeters, Nathan (University of Calgary)
dc.contributor.supervisorBabiuk, Shawn
dc.date.accessioned2024-12-17T17:35:32Z
dc.date.available2024-12-17T17:35:32Z
dc.date.issued2024-12-12
dc.date.submitted2024-12-12T22:40:29Zen_US
dc.degree.disciplineImmunology
dc.degree.levelDoctor of Philosophy (Ph.D.)
dc.description.abstractThe SARS-CoV-2 pandemic has demonstrated the need for faster and more efficient ways to produce diagnostics, therapeutics and vaccines against unknown infectious diseases. This study evaluated the ability of a baculovirus expression vector system (BEVS) to produce immunogenic antigens for use in diagnostic tests and to produce monoclonal antibody (mAb) therapies. This study also evaluated a novel approach to vaccine development: targeting antigen to MHC-II via an immunotargeted vaccine (ITV) as well as a viral vectored vaccine. Using the genetic sequences of SARS-CoV-2, the full-length soluble Spike protein (SS), the S1 domain, receptor binding domain (RBD) and nucleocapsid protein (NP) of SARS-CoV-2 were expressed using the BEVS. These proteins were used to immunize mice to produce mAbs which were proven useful in competitive ELISA development, immunostaining and neutralization of SARS-CoV-2 Wuhan and Delta variants. These mAbs were then further characterized by epitope mapping as well as gene and amino acid sequencing of the variable heavy and light chains. Two unadjuvanted ITVs using the RBD from SARS-CoV-2 were evaluated for their ability to protect ferrets challenged with SARS-CoV-2. The ITVs elicited neutralizing antibody responses after one immunization whereas an adjuvanted subunit vaccine required a boost. Following challenge, ITV immunized ferrets had lower viral titres in nasal washes and were also bright and responsive throughout the duration of challenge. Ferrets immunized with the adjuvanted vaccine and unvaccinated ferrets experienced symptoms consistent with mild to severe clinical disease. A Newcastle disease viral vectored vaccine expressing a pre-fusion stabilized spike protein of SARS-CoV-2 was intranasally immunized into ferrets at low and high doses and the sera was tested for neutralization potential. At both high and low doses, the serum was able to neutralize SARS-CoV-2 Wuhan, Delta B.1.617.2 and Omicron BQ.1 variants. The results from these studies form a basis for further study of these platforms and their potential for implementation in the event of another pandemic as well as for currently circulating viruses in both human and animal populations. This study has the potential to directly contribute to both Canadian and global biosecurity and preparedness.
dc.description.noteFebruary 2025
dc.identifier.urihttp://hdl.handle.net/1993/38716
dc.language.isoeng
dc.rightsopen accessen_US
dc.subjectSARS-CoV-2
dc.subjectVaccines
dc.subjectMonoclonal antibodies
dc.subjectProtein Production
dc.titleThe development and evaluation of medical countermeasures against severe acute respiratory syndrome coronavirus type 2
dc.typedoctoral thesisen_US
local.subject.manitobano
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