Virulence . Generation of an avian influenza DIVA vaccine with a H3-peptide replacement located at HA2 against both highly and low pathogenic H7N9 virus

[tetano]

Virulence


. 2022 Dec;13(1):530-541.
doi: 10.1080/21505594.2022.2040190.
Generation of an avian influenza DIVA vaccine with a H3-peptide replacement located at HA2 against both highly and low pathogenic H7N9 virus


Gang Li ¹ , Juan Feng ¹ , Keji Quan ¹ , Zhihao Sun ¹ , Yuncong Yin ^{1 2 3} , Yinyan Yin ⁴ , Sujuan Chen ^{1 2 3 5} , Tao Qin ^{1 2 3 5} , Daxin Peng ^{1 2 3 5} , Xiufan Liu ^{1 2 5}



Affiliations

• PMID: 35286234
• DOI: 10.1080/21505594.2022.2040190

Abstract

A differentiating infected from vaccinated animals (DIVA) vaccine is an ideal strategy for viral eradication in poultry. Here, according to the emerging highly pathogenic H7N9 avian influenza virus (AIV), a DIVA vaccine strain, named rGD4_HALo-mH3-TX, was successfully developed, based on a substituted 12 peptide of H3 virus located at HA2. In order to meet with the safety requirement of vaccine production, the multi-basic amino acid located at the HA cleavage site was modified. Meanwhile, six inner viral genes from a H9N2 AIV TX strainwere introduced for increasing viral production. The rGD4_HALo-mH3-TX strain displayed a similar reproductive ability with rGD4 and low pathogenicity in chickens, suggesting a good productivity and safety. In immuned chickens, rGD4_HALo-mH3-TX induced a similar antibody level with rGD4 and provided 100% clinical protection and 90% shedding protection against highly pathogenic virus challenge. rGD4_HALo-mH3-TX strain also produced a good cross-protection against low pathogenic AIV JD/17. Moreover, serological DIVA characteristics were evaluated by a successfully established competitive inhibition ELISA based on a 3G10 monoclonal antibody, and the result showed a strong reactivity with antisera of chickens vaccinated with H7 subtype strains but not rGD4_HALo-mH3-TX. Collectedly, rGD4_HALo-mH3-TX is a promising DIVA vaccine candidate against both high and low pathogenic H7N9 subtype AIV.

Keywords: Avian influenza virus; DIVA; H7N9; competitive inhibition ELISA; recombinant vaccine.