1. A vaccine prepared from a non-pathogenic H7N7 virus isolated from natural reservoir conferred protective immunity against the challenge with lethal dose of highly pathogenic avian influenza virus in chickens.
- Author
-
Sakabe S, Sakoda Y, Haraguchi Y, Isoda N, Soda K, Takakuwa H, Saijo K, Sawata A, Kume K, Hagiwara J, Tuchiya K, Lin Z, Sakamoto R, Imamura T, Sasaki T, Kokumai N, Kawaoka Y, and Kida H
- Subjects
- Animals, Antibodies, Viral analysis, Antibodies, Viral biosynthesis, Antibody Specificity, Chickens, Cross Reactions, DNA, Viral genetics, Disease Outbreaks prevention & control, Ducks immunology, Influenza A Virus, H7N7 Subtype immunology, Influenza Vaccines genetics, Influenza Vaccines immunology, Influenza in Birds genetics, Influenza in Birds immunology, Reassortant Viruses growth & development, Ducks virology, Influenza A Virus, H7N7 Subtype physiology, Influenza Vaccines administration & dosage, Influenza in Birds prevention & control, Reassortant Viruses immunology
- Abstract
During 2001-2004, 41 H7 influenza viruses (2 H7N1 and 39 H7N7 strains) were isolated from fecal samples of migratory ducks that flew from Siberia in the autumn of each year to Japan and Mongolia. A phylogenetic analysis of the hemagglutinin (HA) genes of the nine representative isolates revealed that they belonged to the Eurasian lineage and the deduced amino acid sequence at the cleavage site of the HAs represented apathogenic profiles. One of the H7 isolates A/duck/Mongolia/736/02 (H7N7) was chosen from these H7 isolates for the preparation of the test vaccine. To improve the growth potential of A/duck/Mongolia/736/02 (H7N7) in chicken embryos, A/duck/Hokkaido/Vac-2/04 (H7N7) was generated by genetic reassortment between A/duck/Mongolia/736/02 (H7N7) as the donor of the PB2, PB1, PA, HA, NA, and NS genes and A/duck/Hokkaido/49/98 (H9N2) as that of NP and M genes. The test vaccine was prepared as follows; A/duck/Hokkaido/Vac-2/04 (H7N7) was propagated in chicken embryos and the virus in the allantoic fluid was inactivated and adjuvanted to form an oil-in-water emulsion. The test vaccine conferred immunity to chickens, completely protecting the manifestation of clinical signs against the challenge with lethal dose of H7 highly pathogenic avian influenza virus. These results indicate that influenza viruses isolated from natural reservoirs are useful for vaccine strains.
- Published
- 2008
- Full Text
- View/download PDF