1. Potency of an inactivated avian influenza vaccine prepared from a non-pathogenic H5N1 reassortant virus generated between isolates from migratory ducks in Asia.
- Author
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Isoda N, Sakoda Y, Kishida N, Soda K, Sakabe S, Sakamoto R, Imamura T, Sakaguchi M, Sasaki T, Kokumai N, Ohgitani T, Saijo K, Sawata A, Hagiwara J, Lin Z, and Kida H
- Subjects
- Animal Migration, Animals, Animals, Wild, Antibodies, Viral blood, Asia, Chick Embryo, Chickens, Influenza A Virus, H5N1 Subtype genetics, Influenza A Virus, H5N1 Subtype isolation & purification, Influenza A virus immunology, Influenza Vaccines administration & dosage, Influenza Vaccines genetics, Influenza in Birds immunology, Influenza in Birds virology, Reassortant Viruses genetics, Reassortant Viruses isolation & purification, Vaccines, Inactivated administration & dosage, Vaccines, Inactivated genetics, Virus Shedding, Ducks virology, Influenza A Virus, H5N1 Subtype immunology, Influenza Vaccines immunology, Influenza in Birds prevention & control, Reassortant Viruses immunology, Vaccines, Inactivated immunology
- Abstract
A reassortant influenza virus, A/duck/Hokkaido/Vac-1/2004 (H5N1) (Dk/Vac-1/04), was generated between non-pathogenic avian influenza viruses isolated from migratory ducks in Asia. Dk/Vac-1/04 (H5N1) virus particles propagated in embryonated chicken eggs were inactivated with formalin and adjuvanted with mineral oil to form a water-in-oil emulsion. The resulting vaccine was injected intramuscularly into chickens. The chickens were challenged with either of the highly pathogenic avian influenza virus strains A/chicken/Yamaguchi/7/2004 (H5N1) or A/swan/Mongolia/3/2005 (H5N1) at 21 days post-vaccination (p. v.), when the geometric mean serum HI titers of the birds was 64 with the challenge virus strains. The vaccinated chickens were protected from manifestation of disease signs upon challenge with either of the highly pathogenic avian influenza viruses. However, challenge virus was recovered at low titers from the birds at 2 and 4 days post-challenge (p.c.). All 3 chickens challenged at 6 days p.v. died, whereas 3 chickens challenged at 8 days p.v. survived. These results indicate that the present vaccine confers clinical protection and reduction of virus shedding against highly pathogenic avian influenza virus challenge and should be useful as an optional tool in emergency cases.
- Published
- 2008
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