Live recombinant Newcastle disease virus vectored vaccine expressing the haemagglutinin of H9N2 avian influenza virus suppresses viral replication in chickens

ABSTRACT

In 2020, the Y280-lineage H9N2 low-pathogenic avian influenza virus (LPAIV) was introduced into South Korea for the first time. Current vaccines are focused on the control of Y439-like viruses; however, there are continuous reports of decrease in egg production and secondary infections caused by Y280-lineage H9N2 LPAI infection in chickens. Therefore, there is an urgent need to develop effective novel vaccines against Y280-lineage H9N2 LPAI. Most commercialized avian influenza vaccines are oil-adjuvanted inactivated vaccines, which are labour-intensive to administer and require higher dosage. In this study, rK148/Y280-HA, a novel recombinant Newcastle disease virus (NDV) vectored vaccine against Y280-lineage H9N2 LPAI, was developed and evaluated using two mass-applicable administration methods, spray vaccination and drinking water vaccination. Regardless of low serum antibody haemagglutination inhibition titres against NDV and Y280-lineage H9N2 LPAI after applying the rK148/Y280-HA vaccine, vaccination with either administration method protected chickens against virulent NDV and Y280-lineage H9N2 LPAIV after the challenge. Taken together, these results indicate that the rK148/Y280 vaccine can be administered using facile mass-application methods to provide protection against the Y280-lineage LPAI.

RESEARCH HIGHLIGHTS

• NDV vectored vaccine harbouring Y280-lineage H9N2 HA protein was successfully generated.

• NDV vectored vaccine provides protection against NDV.

• NDV vectored vaccine with H9N2 HA protects against homologous H9N2 LPAIV.

KEYWORDS:

• NDV vectored vaccine
• H9N2
• LPAIV
• Y280-lineage
• spray vaccination
• drinking water vaccination

Acknowledgements

We thank Hyo-Sun Ju, Su-Bin Park, and Su-Jin Ji for providing technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [grant number NRF-2018M3A9H4056535], and by the Animal and Plant Quarantine Agency, Republic of Korea (Project Code No. Z-1543070-2018-18-01).