Potency and efficacy of a low pathogenic H5N2 inactivated vaccine against challenge with a Malaysian H5N1 highly pathogenic avian influenza virus

Azizah D., . and Surian M. N., . and Sharifah S. H., . and Omar A. R., . and Maizan M., . and Ong G. H., . and Suzana K., . and Aini I., . Potency and efficacy of a low pathogenic H5N2 inactivated vaccine against challenge with a Malaysian H5N1 highly pathogenic avian influenza virus. pp. 1-6. ISSN 9128-2506

The potency and efficacy of an avian influenza (AI) H5N2 inactivated vaccine that was developed at Veterinary Research Institute Ipoh was tested. The percentage sequence identity of the HA gene of the H5N2 vaccine virus to the challenge virus A/chicken/Malaysia/5858/04 (H5N1) was 88.2 by nucleotide and 90 by amino acid sequences similarities respectively. As for the HAI segment the nucleotide sequence similarities were 88.3 and by amino acid sequence 87.7.For potency testing the heterologous killed H5N2 AI vaccine formulated as an oil emulsion was administered only once subcutaneously in twenty five two-week old commercial broiler chickens. The HI antibodies were not detectable at week 1 post vaccination. The HI GMT attained was 30 63 200 54 and 32 by week 2 3 4 5 and 6 post vaccinations. Efficacy study was conducted on ten SPF chickens at week 3 post vaccination. 60 of the birds (6/10) with HI titres 64 - 128 survived the challenged. H5N1 challenge virus was reisolated from all the birds with HI titre 32 that died and each of the birds that survived with HI titres of 64 and 128 from the oropharynx and cloaca at day 3 post challenge. This vaccine protected 60 of chickens against mortality and did not prevent shedding after challenged with a HPAI H5N1 virus.

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

Abstract

The potency and efficacy of an avian influenza (AI) H5N2 inactivated vaccine that was developed at Veterinary Research Institute Ipoh was tested. The percentage sequence identity of the HA gene of the H5N2 vaccine virus to the challenge virus A/chicken/Malaysia/5858/04 (H5N1) was 88.2 by nucleotide and 90 by amino acid sequences similarities respectively. As for the HAI segment the nucleotide sequence similarities were 88.3 and by amino acid sequence 87.7.For potency testing the heterologous killed H5N2 AI vaccine formulated as an oil emulsion was administered only once subcutaneously in twenty five two-week old commercial broiler chickens. The HI antibodies were not detectable at week 1 post vaccination. The HI GMT attained was 30 63 200 54 and 32 by week 2 3 4 5 and 6 post vaccinations. Efficacy study was conducted on ten SPF chickens at week 3 post vaccination. 60 of the birds (6/10) with HI titres 64 - 128 survived the challenged. H5N1 challenge virus was reisolated from all the birds with HI titre 32 that died and each of the birds that survived with HI titres of 64 and 128 from the oropharynx and cloaca at day 3 post challenge. This vaccine protected 60 of chickens against mortality and did not prevent shedding after challenged with a HPAI H5N1 virus.

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Item Type:	Article
AGROVOC Term:	Avian influenza virus
AGROVOC Term:	Inactivated vaccines
AGROVOC Term:	Broiler chickens
AGROVOC Term:	Isolation techniques
AGROVOC Term:	PCR
AGROVOC Term:	Gene sequence
AGROVOC Term:	Vaccination
AGROVOC Term:	Nucleotide sequence
AGROVOC Term:	Amino acid sequences
AGROVOC Term:	Immunity
Depositing User:	Mr. AFANDI ABDUL MALEK
Last Modified:	24 Apr 2025 00:54
URI:	http://webagris.upm.edu.my/id/eprint/8368

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