Date of Award
Doctor of Philosophy
Veterinary Microbiology and Preventive Medicine
Merlin L. Kaeberle
Immunization of young lambs against parainfluenza virus 3 (PI-3) is a major problem due to the presence of maternal antibodies that interfere with an active immune response. The objective of this experimentation was to develop a heterotypic vaccine that would overcome that blocking effect;Antiserums were produced in lambs against bovine PI-3 (BPI-3), human PI-3 (HPI-3), Sendai virus and simian virus-5 (SV-5). The titer and specificity of the antiserums were determined by hemagglutination inhibition (HI) test, enzyme linked immunosorbent assay (ELISA), Western immunoblot assay (WIA), and radioimmunoprecipitation assay (RIPA);These sheep antiserums demonstrated a close antigenic relationship between BPI-3 and HPI-3 viruses. Sendai virus was also found to share some epitopes with the PI-3 viruses. Antigenic crossreactivity of SV-5 antiserum was limited to the nucleoprotein of other viruses;Lambs with variant levels of PI-3 virus maternal antibodies were vaccinated with inactivated virus preparations of either bovine PI-3, human PI-3, or Sendai virus. The viruses were inactivated with binary ethylenimine, adjuvanted with aluminum hydroxide and administered in doses of 25 or 50 [mu]g (as protein) subcutaneously to groups of lambs. Primary immunization in the presence of maternal antibodies failed to induce a detectable response to bovine PI-3 virus. A marked antibody response developed to secondary immunization with BPI-3 virus vaccine in lambs with low maternal antibody titers (≤8). However, the secondary response was limited in lambs with high initial maternal antibody titers (≥16);Groups of lambs that had not been vaccinated or administered a single dose of Bovine PI-3 or Human PI-3 or two doses of Bovine PI-3 vaccine were challenged with an ovine strain of PI-3 virus. Clinical signs were most dramatic in the unvaccinated controls. The once-vaccinated Bovine PI-3 group also was markedly affected but the disease was much less severe in the once-vaccinated Human PI-3 and twice-vaccinated Bovine PI-3 groups. Results of this experimentation indicated some potential for the use of HPI-3 virus vaccine for control of PI-3 virus infection in lambs.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Hussain, Manzoor, "Recognition of paramyxovirus antigens by lambs " (1992). Retrospective Theses and Dissertations. 9837.