Assessing potential pathogenicity of novel highly pathogenic avian influenza (H5N6) viruses isolated from Mongolian
Bao Tuan Duong1, Duc Duong Than1, Ulaankhuu Ankhanbaatar2
1Zoonosis Research Center, Department of Infection Biology, School of Medicine, Wonkwang University, Iksan, Korea.
Abstract:
Several novel highly pathogenic avian influenza (HPAIVs) A(H5N6) viruses were reported in Mongolia in 2020, some of which included host-specific markers associated with mammalian infection. However, their pathogenicity has not yet been investigated. Here, we isolated and evaluate two novel genotypes of A(H5N6) subtype in Mongolia during 2018-2019 (A/wildDuck/MN/H5N6/2018-19). Their evolution pattern and molecular characteristics were evaluated using gene sequencing and their pathogenicity was determined using a mouse model. We also compared their antigenicity with previous H5 Clade 2.3.4.4 human isolates by cross-hemagglutination inhibition (HI). Our data suggests that A/wildDuck/MN/H5N6/2018-19 belongs to clade 2.3.4.4h, and maintains several residues associated with mammal adaptation. In addition, our evaluations revealed that their isolates are less virulent in mice than the previously identified H5 human isolates. However, their antigenicity is distinct from other HPAIVs H5 clade 2.3.4.4, thus supporting their continued evaluation as potential infection risks and the preparation of novel candidate vaccines for their neutralization.
Insights
Novel highly pathogenic avian influenza (H5N6) viruses in Mongolia show potential for mammal adaptation but reduced virulence in mice. Their distinct antigenicity necessitates ongoing risk assessment and vaccine development.
Area of Science:
- Virology
- Infectious Diseases
- Public Health
Background:
- Novel highly pathogenic avian influenza viruses (HPAIVs) A(H5N6) were identified in Mongolia in 2020.
- Some isolates possessed markers suggesting potential for mammalian infection, necessitating pathogenicity and antigenic studies.
Purpose of the Study:
- To isolate and characterize novel A(H5N6) viruses from Mongolia.
- To evaluate their evolutionary patterns, molecular features, pathogenicity in a mouse model, and antigenicity compared to existing H5 isolates.
Main Methods:
- Isolation and genetic sequencing of A(H5N6) viruses from Mongolian wild ducks (2018-2019).
- Pathogenicity assessment in a mouse model.
- Cross-hemagglutination inhibition (HI) assays to compare antigenicity with human H5 isolates.
Main Results:
- Two novel A(H5N6) genotypes, belonging to clade 2.3.4.4h, were identified.
- These viruses retain mammalian-adaptive residues but exhibit lower virulence in mice compared to previous H5 human isolates.
- A distinct antigenic profile was observed compared to other HPAIVs H5 clade 2.3.4.4.
Conclusions:
- The Mongolian A(H5N6) viruses represent a potential zoonotic risk due to mammalian-adaptive markers and distinct antigenicity.
- Continued surveillance and development of targeted vaccines are recommended for effective neutralization and control.
