title: Influenza A virus hemagglutinin protein subunit vaccine elicits vaccine-associated enhanced respiratory disease in pigs.
abstract: Vaccine-associated enhanced respiratory disease (VAERD) can occur when pigs are challenged with heterologous virus in the presence of non-neutralizing but cross-reactive antibodies elicited by whole inactivated virus (WIV) vaccine. The aim of this study was to compare the effects of heterologous δ1-H1N2 influenza A virus (IAV) challenge of pigs after vaccination with 2009 pandemic H1N1 virus (H1N1pdm09) recombinant hemagglutinin (HA) subunit vaccine (HA-SV) or temperature-sensitive live attenuated influenza virus (LAIV) vaccine, and to assess the role of immunity to HA in the development of VAERD. Both HA-SV and LAIV vaccines induced high neutralizing antibodies to virus with homologous HA (H1N1pdm09), but not heterologous challenge virus (δ1-H1N2). LAIV partially protected pigs, resulting in reduced virus shedding and faster viral clearance, as no virus was detected in the lungs by 5 days post infection (dpi). HA-SV vaccinated pigs developed more severe lung and tracheal lesions consistent with VAERD following challenge. These results demonstrate that the immune response against the HA protein alone is sufficient to cause VAERD following heterologous challenge.
authors: Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Avenue, PO Box 70, Ames, IA 50010, USA.
authors: Daniela S
authors: DS
authors: Rajão
authors: Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Avenue, PO Box 70, Ames, IA 50010, USA.
authors: Crystal L
authors: CL
authors: Loving
authors: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1648 Vet Med, Ames, IA 50011, USA.
authors: Phillip C
authors: PC
authors: Gauger
authors: Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Avenue, PO Box 70, Ames, IA 50010, USA.
authors: Pravina
authors: P
authors: Kitikoon
authors: Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Avenue, PO Box 70, Ames, IA 50010, USA. Electronic address: amy.vincent@ars.usda.gov.
authors: Amy L
authors: AL
authors: Vincent
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology*; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines / Q000009:adverse effects* / Q000276:immunology; D008168:Lung / Q000473:pathology; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D012140:Respiratory Tract Diseases / Q000139:chemically induced / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000139:chemically induced* / Q000517:prevention & control; D014132:Trachea / Q000473:pathology; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000276:immunology; D022223:Vaccines, Subunit / Q000009:adverse effects / Q000276:immunology; D017201:Virus Shedding
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; D022223:Vaccines, Subunit
keywords: Hemagglutinin; Influenza; Pigs; VAERD; Vaccine