Fig. 7: Effective protection after two-month DelNS1-H5N1 immunization.
A Illustration of schedule of immunization, virus challenge and sacrifice for BALB/c mice. Mice were intranasally vaccinated with DelNS1-cH5N1 (106 pfu, n = 16) or mock-vaccinated (n = 12). B Serum was collected at week 8 and tested for IgG titers against cH5N1 (DelNS1-cH5N1) virus or H5N1-HA1 protein and micro-neutralization titers against live viruses. Levels of IgA against H5N1-HA1 in BAL were measured at week 8 following DelNS1-mH5N1 vaccination. C At 8 weeks after immunization, mice were challenged with cattle H5N1 virus (5000 pfu); body weights were monitored for 14 days and viral titers in the lungs, NT and brain were measured at 4 dpi (n = 4 for mock group; n = 8 for DelNS1-cH5N1 two-month group). D Mice were intranasally vaccinated with DelNS1-mH5N1 (106 pfu, n = 16) or mock-vaccinated (n = 12), and serum collected at week 8 tested for IgG titers against mH5N1 (DelNS1-mH5N1) virus or H5N1-HA1 protein and micro-neutralization titers against live virus. BAL levels of IgA recognizing H5N1-HA1 were measured at week 8 after DelNS1-mH5N1 vaccination. E Eight weeks after immunization, mice were challenged with mink H5N1 virus (104 pfu); body weights were monitored for 14 days and viral titers in the lungs and NT were measured at 4 dpi (n = 4 for mock group; n = 8 for DelNS1-mH5N1 two-month group). LOD limit of detection. Data represent mean values ± SD of results. Statistical analysis was performed using 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.
