Single Dose of Bivalent H5 and H7 Influenza Virus-Like Particle Protects Chickens Against Highly Pathogenic H5N1 and H7N9 Avian Influenza Viruses

Abstract

Both H5N1 and H7N9 subtype avian influenza viruses cause enormous economic losses and pose considerable threats to public health. Bivalent vaccines against both two subtypes are more effective in control of H5N1 and H7N9 viruses in poultry and novel egg-independent vaccines are needed. Herein, H5 and H7 virus like particle (VLP) were generated in a baculovirus expression system and a bivalent H5+H7 VLP vaccine candidate was prepared by combining these two antigens. Single immunization of the bivalent VLP or commercial inactivated vaccines elicited effective antibody immune responses, including hemagglutination inhibition, virus neutralizing and HA-specific IgG antibodies. All vaccinated birds survived lethal challenge with highly pathogenic H5N1 and H7N9 viruses. Furthermore, the bivalent VLP significantly reduced viral shedding and virus replication in chickens, which was comparable to that observed for the commercial inactivated vaccine. However, the bivalent VLP was better than the commercial vaccine in terms of alleviating pulmonary lesions caused by H7N9 virus infection in chickens. Therefore, our study suggests that the bivalent H5+H7 VLP vaccine candidate can serve as a critical alternative for the traditional egg-based inactivated vaccines against H5N1 and H7N9 avian influenza virus infection in poultry.

Respiratory Viruses and Virus-like Particle Vaccine Development: How Far Have We Advanced?

“…A single dose of this VLP vaccine was sufficient to mount protection in immunized chickens against the highly pathogenic avian influenza virus challenge. Compared to the commercialized trivalent inactivated vaccines, the bivalent VLP vaccine incurred lesser pulmonary pathologies, and much of the lesions and inflammatory responses were alleviated [ 28 ]. One study compared the range of protection elicited by both mammalian cell-derived VLPs and protein subunit vaccines.…”

The relationship among avian influenza, gut microbiota and chicken immunity: an updated overview

“…Avian influenza is a worldwide zoonotic disease and is usually accompanied by significant disruption of the poultry industry as well as epidemics and pandemics ( Adlhoch et al, 2021 ; Hu et al, 2021 ). It is well known that the poultry entero-tropism of low pathogenic avian influenza ( LPAI ) is higher than that of highly pathogenic avian influenza ( HPAI ), which is more linked to the respiratory epithelium ( Post et al, 2012 ).…”

“…The HA surface protein is the major antigenic determinant resulting in clinical signs and immune responses ( Perdue, 2008 ; Hu et al, 2021 ). HA is a polyprotein with a rounded head cleaved into two subunits (HA-2 and HA-1).…”

“…Nevertheless, recent studies have reported a much broader tissue tropism of LPAI viruses in the brain, spleen, cardiac, hepatic, and renal tissues ( Post et al, 2012 , 2013 ). Stimulating a GIT immune reaction by the rapid replication of LPAI viruses is crucial in protecting birds from the lethal impact of HPAI viruses ( Hu et al, 2021 ).…”

A single immunization with H5N1 virus-like particle vaccine protects chickens against divergent H5N1 influenza viruses and vaccine efficacy is determined by adjuvant and dosage

“…Vaccination is considered one of the current strategies to prevent and control the spread of H5N1 HPAIV in China [ 7 ]. However, the current commercial whole virus inactivated vaccines do not provide optimal protection against infection by novel H5N1 variants due to antigenic mismatch between vaccine and circulating virus stains.…”