Fig. 4: A/AW/SC/2021 (A/AW) H5-MNP vaccine elicits seroconverting antibody- and cell-mediated immune responses when administered IM or IN in NHPs primed with qNIV.

a Rhesus macaques (nonhuman primates; NHPs) were immunized by a two-dose quadrivalent nanoparticle seasonal influenza vaccine (qNIV; 60 µg HA/strain) with 75 µg Matrix-M adjuvant (IM) on Study Days 0 and 21 (n = 10). NHPs (n = 5/group) were then administered two sequential booster doses of H5-MNP vaccine (either two IM 60 μg doses of HA or one IN dose of 240 μg HA, followed by one IN dose of 60 μg HA; all with 75 μg Matrix-M adjuvant) on Study Days 83 and 139. Hemagglutinin inhibiting (HAI) antibody titers (n = 10 on Day 0, 35, and 83, and 5 on Day 97, 139, and 153 (IM or IN)) (b) and pseudovirus neutralizing antibody titers (c) against A/AW/SC/2021 were evaluated in sera collected on Study Days indicated on the X-axis (n = 10 on Day 0, 35, and 83, and 5 on Day 97, 139, and 153 (IM or IN)). d Triple Th1⁺ CD4⁺ T-cell responses were evaluated in PBMCs collected on Study Days indicated on the X-axis (n = 10 on Day 0 and 35, 9 on Day 83, 5 on Day 97 (IM or IN), and 4 or 5 on Day 153 for IM or IN, respectively). The cells were stimulated with A/AW HA. Colored symbols represent individual data points, and bars represent group geometric mean titers. Error bars represent 95% confidence intervals, and the horizontal dashed line represents the assay limit of detection (LOD) or quantification (LOQ) or the seroconverting threshold titer of 1:40. Differences between groups were evaluated by the Mann–Whitney U Test (two-tailed). Source data are provided as a Source Data file. Created by Microsoft^® Office Visio Web App 2025.