Degree Type

Thesis

Date of Award

1-1-2006

Degree Name

Master of Science

Department

Veterinary Microbiology and Preventive Medicine

Major

Veterinary Microbiology

Abstract

The objectives of this research were to determine if inactivated PRRSV vaccines derived from two strains of differing GP5 glycosylation and a strain enzymatically treated to remove GP5 glycans could provide protection from infection and disease and induce a heterologous and neutralizing immune response. Three studies involving three week old PRRS negative and Mycoplasma hyopneumoniae negative pigs were performed. The pigs were immunized three times at two week intervals, challenged 56 days after the initial immunization and necropsied two weeks post challenge. Serologic responses were measured at two week intervals using PRRS IDEXX ELISA and fluorescent focus neutralization. Gross lung lesions, histopathology and qRT-PCR were used to determine protection at necropsy. Crude viral antigen vaccines were able to stimulate a humoral immune response prior to challenge with live PRRSV in pigs in each of the three studies. This response was non-protective and characterized by antibody production to the nucleocapsid protein. In the third study, a neutralizing immune response was induced prior to challenge in some pigs receiving crude viral antigen vaccines prepared from two PRRSV strains. However, in all studies the immune response stimulated by inactivated vaccines was unable to provide protection from infection or disease.

Copyright Owner

Jason David Hocker

Language

en

OCLC Number

71339601

File Format

application/pdf

File Size

98 pages

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