TY - JOUR
T1 - Safety, efficacy, and immunogenicity of a modified-live equine influenza virus vaccine in ponies after induction of exercise-induced immunosuppression
AU - Lunn, D. Paul
AU - Hussey, Steve
AU - Sebring, Randy
AU - Rushlow, Keith E.
AU - Radecki, Steve V.
AU - Whitaker-Dowling, Patricia
AU - Youngner, Julius S.
AU - Chambers, Thomas M.
AU - Holland, Robert E.
AU - Horohov, David W.
PY - 2001/3/15
Y1 - 2001/3/15
N2 - Objective - To determine safety, efficacy, and immunogenicity of an intranasal cold-adapted modified-live equine influenza virus vaccine administered to ponies following induction of exercise-induced immunosuppression. Design - Prospective study. Animals - Fifteen 9- to 15-month old ponies that had not had influenza. Procedure - Five ponies were vaccinated after 5 days of strenuous exercise on a high-speed treadmill, 5 were vaccinated without undergoing exercise, and 5 were not vaccinated or exercised and served as controls. Three months later, all ponies were challenged by nebulization of homologous equine influenza virus. Clinical and hematologic responses and viral shedding were monitored, and serum and nasal secretions were collected for determination of influenza-virus-specific antibody isotype responses. Results - Exercise caused immunosuppression, as indicated by depression of lymphocyte proliferation in response to pokeweed mitogen. Vaccination did not result in adverse clinical effects, and none of the vaccinated ponies developed clinical signs of infection following challenge exposure. In contrast, challenge exposure caused marked clinical signs of respiratory tract disease in 4 control ponies. Vaccinated and control ponies shed virus after challenge exposure. Antibody responses to vaccination were restricted to serum IgGa and IgGb responses in both vaccination groups. After challenge exposure, ponies in all groups generated serum IgGa and IgGb and nasal IgA responses. Patterns of serum hemagglutination inhibition titers were similar to patterns of IgGa and IgGb responses. Conclusions and Clinical Relevance - Results suggested that administration of this MLV vaccine to ponies with exercise-induced immunosuppression was safe and that administration of a single dose to ponies provided clinical protection 3 months later.
AB - Objective - To determine safety, efficacy, and immunogenicity of an intranasal cold-adapted modified-live equine influenza virus vaccine administered to ponies following induction of exercise-induced immunosuppression. Design - Prospective study. Animals - Fifteen 9- to 15-month old ponies that had not had influenza. Procedure - Five ponies were vaccinated after 5 days of strenuous exercise on a high-speed treadmill, 5 were vaccinated without undergoing exercise, and 5 were not vaccinated or exercised and served as controls. Three months later, all ponies were challenged by nebulization of homologous equine influenza virus. Clinical and hematologic responses and viral shedding were monitored, and serum and nasal secretions were collected for determination of influenza-virus-specific antibody isotype responses. Results - Exercise caused immunosuppression, as indicated by depression of lymphocyte proliferation in response to pokeweed mitogen. Vaccination did not result in adverse clinical effects, and none of the vaccinated ponies developed clinical signs of infection following challenge exposure. In contrast, challenge exposure caused marked clinical signs of respiratory tract disease in 4 control ponies. Vaccinated and control ponies shed virus after challenge exposure. Antibody responses to vaccination were restricted to serum IgGa and IgGb responses in both vaccination groups. After challenge exposure, ponies in all groups generated serum IgGa and IgGb and nasal IgA responses. Patterns of serum hemagglutination inhibition titers were similar to patterns of IgGa and IgGb responses. Conclusions and Clinical Relevance - Results suggested that administration of this MLV vaccine to ponies with exercise-induced immunosuppression was safe and that administration of a single dose to ponies provided clinical protection 3 months later.
UR - http://www.scopus.com/inward/record.url?scp=0035869622&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035869622&partnerID=8YFLogxK
U2 - 10.2460/javma.2001.218.900
DO - 10.2460/javma.2001.218.900
M3 - Article
C2 - 11294315
AN - SCOPUS:0035869622
SN - 0003-1488
VL - 218
SP - 900
EP - 906
JO - Journal of the American Veterinary Medical Association
JF - Journal of the American Veterinary Medical Association
IS - 6
ER -