Safety, Immunogenicity, and Protective Efficacy of an H5N1 Chimeric Cold-Adapted Attenuated Virus Vaccine in a Mouse Model

Abstract

H5N1 influenza virus is a threat to public health worldwide. The virus can cause severe morbidity and mortality in humans. We constructed an H5N1 influenza candidate virus vaccine from the A/chicken/Guizhou/1153/2016 strain that was recommended by the World Health Organization. In this study, we designed an H5N1 chimeric influenza A/B vaccine based on a cold-adapted (ca) influenza B virus B/Vienna/1/99 backbone. We modified the ectodomain of H5N1 hemagglutinin (HA) protein, while retaining the packaging signals of influenza B virus, and then rescued a chimeric cold-adapted H5N1 candidate influenza vaccine through a reverse genetic system. The chimeric H5N1 vaccine replicated well in eggs and the Madin-Darby Canine Kidney cells. It maintained a temperature-sensitive and cold-adapted phenotype. The H5N1 vaccine was attenuated in mice. Hemagglutination inhibition (HAI) antibodies, micro-neutralizing (MN) antibodies, and IgG antibodies were induced in immunized mice, and the mucosal IgA antibody responses were detected in their lung lavage fluids. The IFN-γ-secretion and IL-4-secretion by the mouse splenocytes were induced after stimulation with the specific H5N1 HA protein. The chimeric H5N1 candidate vaccine protected mice against lethal challenge with a wild-type highly pathogenic avian H5N1 influenza virus. The chimeric H5 candidate vaccine is thus a potentially safe, attenuated, and reassortment-incompetent vaccine with circulating A viruses.

An avian-origin internal backbone effectively increases the H5 subtype avian influenza vaccine candidate yield in both chicken embryonated eggs and MDCK cells

“…In China, although a diverse range of vaccine types, including attenuated live vaccines ( Sun, et al, 2023 ), recombinant vaccines ( Qiao, et al, 2009 ; Zhao, et al, 2024 ), virus-like particles ( Park, et al, 2023 ), DNA vaccines ( Xu, et al, 2022a ), have been developed, inactivated vaccines are the predominant strategy for preventing and controlling H5 subtype influenza. In clinical applications, developing high-titer vaccines is crucial for cost control while considering factors such as the inherent specificity of a given strain ( Ping, et al, 2015 ), matrix elements ( Kistner, et al, 1998 ; Pau, et al, 2001 ; Tree, et al, 2001 ), culture, and infection ( Frensing, et al, 2014 ; Klenk et al, 1975 ).…”

A live attenuated influenza B virus vaccine expressing RBD elicits protective immunity against SARS-CoV-2 in mice

“…ELISA was used to measure IgG titers in the serum and IgA concentrations in the lung lavage fluids, as previously described ( Sun et al, 2021 ). A high-sorbent 96-well microplate was coated with HA (Sino Biological, 40,157-V08H1) or RBD protein (Sino Biological, 40,592-V08H) at a concentration of 5 µg/mL at 4 °C overnight.…”

Viral vectored vaccines: design, development, preventive and therapeutic applications in human diseases

“…Our group constructed an H5N1 chimeric IAV/B vaccine based on a cold-adapted (ca) IBV B/Vienna/1/99 backbone. 239 Modified HA of H5N1 was inserted while the packaging signals of HA of IBV were retained. The recombinant virus maintained a temperaturesensitive and cold-adapted phenotype.…”