Immunogenicity and protective efficacy of an elastase-dependent live attenuated swine influenza virus vaccine administered intranasally in pigs.

Abstract

Influenza A virus is an important respiratory pathogen of swine that causes significant morbidity and economic impact on the swine industry. Vaccination is the first choice for prevention and control of influenza infections. Live attenuated influenza vaccines (LAIV) are approved for use in humans and horses and their application provides broad protective immunity, however no LAIV against swine influenza virus (SIV) exists in the market. Previously we reported that an elastase-dependent mutant SIV A/Sw/Sk-R345V (R345V) derived from A/Sw/Saskatchewan/18789/02 (H1N1) (SIV/Sk02) is highly attenuated in pigs. Two intratracheal administrations of R345V induced strong cell-mediated and humoral immune responses and provided a high degree of protection to antigenically different SIV infection in pigs. Here we evaluated the immunogenicity and the protective efficacy of R345V against SIV infection by intranasal administration, the more practical route for vaccination of pigs in the field. Our data showed that intranasally administered R345V live vaccine is capable of inducing strong antigen-specific IFN-γ response from local tracheo-bronchial lymphocytes and antibody responses in serum and respiratory mucosa after two applications. Intranasal vaccination of R345V provided pigs with complete protection not only from parental wild type virus infection, but also from homologous antigenic variant A/Sw/Indiana/1726/88 (H1N1) infection. Moreover, intranasal administration of R345V conferred partial protection from heterologous subtypic H3N2 SIV infection in pigs. Thus, R345V elastase-dependent mutant SIV can serve as a live vaccine against antigenically different swine influenza viruses in pigs.

• Authors: Aleksandar Masic, Xinya Lu, Junwei Li, George K Mutwiri, Lorne A Babiuk, Earl G Brown, Yan Zhou
• Journal: Vaccine (Vaccine) Vol. 28 Issue 43 Pg. 7098-108 (Oct 08 2010) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 20708697 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Antibodies, Viral
• Influenza Vaccines
• Vaccines, Attenuated
• Interferon-gamma

Topics

• Administration, Intranasal
• Animals
• Antibodies, Viral (blood)
• Antibody Formation
• Cell Line
• Cross Protection
• Dogs
• Enzyme-Linked Immunosorbent Assay (veterinary)
• Hemagglutination Inhibition Tests (veterinary)
• Influenza A Virus, H1N1 Subtype (immunology)
• Influenza Vaccines (administration & dosage, immunology)
• Interferon-gamma (immunology)
• Lung (immunology, pathology)
• Orthomyxoviridae Infections (immunology, prevention & control, veterinary)
• Swine (immunology)
• Swine Diseases (immunology, prevention & control)
• Vaccines, Attenuated (immunology)