Analysis of IgG Antibody Subtype Variation in Quarter Horse Foals Following Vaccination With West Nile Virus Vaccine

Open Access
Smith, Lauren Olivia
Area of Honors:
Veterinary and Biomedical Sciences
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Suzanne Myers, Thesis Supervisor
  • Arthur Hattel, Thesis Supervisor
  • Lester C Griel Jr., Honors Advisor
  • west nile
  • antibody
  • IgG
  • foals
  • subtyping profiles
Currently, the only significant protection against West Nile Virus (WNV) infection in horses is through vaccination. There is a strong need to evaluate the current vaccines among each other for efficacy to determine optimum vaccination protocols. Subtyping antibody profiles may be crucial to understanding how to tailor commercially available vaccines to improve defense against WNV. Vaccines exhibiting particular subtype profiles may be more efficacious resulting in greater protection, a decreased need for multiple vaccinations, or both strategies. Serum antibody titers of 13 quarter horse foals vaccinated with two commercially available vaccines, an inactivated whole virus and a canarypox-vectored recombinant vaccine, were evaluated by ELISA to determine the subtypes of IgG stimulated by the vaccines and to evaluate the strength of the immune response. Inactivated whole virus vaccinated foals had increased antibody titers of the IgGb and IgGa subtypes in both primary and secondary immune responses. The recombinant vaccinated foals had increased antibody titers of IgGb, IgGa, and IgG(T) after a delay of approximately 8 weeks. The killed whole virus vaccine appeared to stimulate humoral immunity at the level of B-cell activation. The recombinant vaccine may stimulate immunity to WNV through T-cell activation and a delayed TH2 response which may then stimulate a memory cell response to WNV.