Moderately-high humoral antibody responses to a H5N2 inactivated vaccine did not suppress shedding of highly pathogenic H5N1 avian influenza virus during challenge

Sharifah S. H., . and Hasuzana K., . and Suriani M. N., . and Maizan M., . and Ong G. H., . and Azizah D., . and Omar A. R., . and Aini I., . Moderately-high humoral antibody responses to a H5N2 inactivated vaccine did not suppress shedding of highly pathogenic H5N1 avian influenza virus during challenge. pp. 27-30. ISSN 9128-2506

Twelve SPF chickens with moderately high-titred HI antibodies of 7 log‚‚ and 8 log‚‚ achieved at week 4 post-vaccination after a single vaccination with an inactivated whole-H5N2 virus vaccine developed at Veterinary Research Institute Ipoh were selected for efficacy and shedding studies. The H5N2 vaccine virus shares approximately 88.2 homology to the HA gene of the H5N1 challenge virus. The chickens with moderately high titred-HI humoral antibodies provided 100 protection against mortality and morbidity after challenged with a lethal highly pathogenic H5N1 Malaysian strain. The challenge H5N1 virus was reisolated from pooled cloacal swabs of chickens with HI titres of 7 log‚‚ and 8 log‚‚ at 3 days post challenged however was not reisolated from the pooled oropharyngeal swabs. The virus titre at reisolation was 10EID‚‚/0.1 ml in pooled cloacal samples from both the 7 log‚‚ and 8 log‚‚ HI titred-chickens. There was no challenge H5N1 virus reisolated from chickens with HI titre of 9 log‚‚ . This study demonstrated that chickens with moderately high HI humoral antibodies protect chickens against clinical disease and mortality did not fully prevent infection however was able to reduce virus shed via the cloaca and oropharynx.

Full text available from: Official URL: https://www.mavma.org.my/2013-volume-25-issue-no-1...

Abstract

Twelve SPF chickens with moderately high-titred HI antibodies of 7 log‚‚ and 8 log‚‚ achieved at week 4 post-vaccination after a single vaccination with an inactivated whole-H5N2 virus vaccine developed at Veterinary Research Institute Ipoh were selected for efficacy and shedding studies. The H5N2 vaccine virus shares approximately 88.2 homology to the HA gene of the H5N1 challenge virus. The chickens with moderately high titred-HI humoral antibodies provided 100 protection against mortality and morbidity after challenged with a lethal highly pathogenic H5N1 Malaysian strain. The challenge H5N1 virus was reisolated from pooled cloacal swabs of chickens with HI titres of 7 log‚‚ and 8 log‚‚ at 3 days post challenged however was not reisolated from the pooled oropharyngeal swabs. The virus titre at reisolation was 10EID‚‚/0.1 ml in pooled cloacal samples from both the 7 log‚‚ and 8 log‚‚ HI titred-chickens. There was no challenge H5N1 virus reisolated from chickens with HI titre of 9 log‚‚ . This study demonstrated that chickens with moderately high HI humoral antibodies protect chickens against clinical disease and mortality did not fully prevent infection however was able to reduce virus shed via the cloaca and oropharynx.

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Item Type:	Article
AGROVOC Term:	Ducks
AGROVOC Term:	Chickens
AGROVOC Term:	Avian influenza virus
AGROVOC Term:	Humoral immunity
AGROVOC Term:	Vaccination
AGROVOC Term:	Vaccines
AGROVOC Term:	Isolation techniques
AGROVOC Term:	Inactivated vaccines
AGROVOC Term:	Nucleotide sequence
AGROVOC Term:	Amino acid sequences
Depositing User:	Mr. AFANDI ABDUL MALEK
Last Modified:	24 Apr 2025 00:54
URI:	http://webagris.upm.edu.my/id/eprint/8372

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