Fig. 4: DelNS1-H5N1 vaccines provide protection against different 2.3.4.4b clade viruses.

A Illustration of schedule of immunization, virus challenge and sacrifice for BALB/c mice. Mice were intranasally vaccinated with DelNS1-cH5N1 (10⁶ pfu, n = 32, two independent experiments), DelNS1-mH5N1 (10⁶ pfu, n = 32, two independent experiments) or mock-vaccinated (n = 16, two independent experiments), then challenged with either cattle H5N1 virus (5000 pfu) or mink H5N1 virus (10⁴ pfu) 4 weeks after immunization. B Mice immunized with DelNS1-cH5N1 and challenged with cattle H5N1 virus; body weights were monitored for 14 days and viral titers in the lungs, NT and brain were measured at 4 dpi. C Mice immunized with DelNS1-mH5N1 and challenged with mink H5N1 virus; body weights were monitored for 14 days and viral titers in the lungs, NT and brain were measured at 4 dpi. D DelNS1-cH5N1-vaccinated mice were challenged with mink H5N1 virus, and body weights monitored for 14 days and viral titers in the lungs, NT and brain measured at 4 dpi. E DelNS1-mH5N1-vaccinated mice were challenged with cattle H5N1, and body weights monitored for 14 days and viral titers in the lungs, NT and brain measured at 4 dpi. LOD: limit of detection. Data represents mean values ± SD of results. Statistical comparisons between means were performed by Student’s t-test (two-tailed). Mouse cartoon was created in BioRender. Wang, P. (2025) https://BioRender.com/n83i107. Source data are provided as a Source Data file.