Extended Data Fig. 4: H5N1 vaccination elicits strong H5 stalk-reactive antibodies in children.
From: Immune history shapes human antibody responses to H5N1 influenza viruses
Sera samples were obtained from participants (n = 100) before (day 0) and 28 days after receiving a first and second dose of an unadjuvanted A/Vietnam/1203/2004 H5N1 vaccine in 2005-2006. We quantified IgG binding to a ‘headless’ A/Vietnam/1203/2004 H5 stalk (a-c), and we calculated titer fold change by dividing day 28 post-boost titers by day 0 titers (d). We also measured antibody binding and fold change to clade 1 A/Vietnam/1203/2004 full length H5 HA (e-h) and clade 2.3.4.4b A/Pheasant/New York/22-009066-011/2022 full length H5 HA (i-l). Vertical dashed lines mark years of the 1957 H2N2 and 1968 H3N2 pandemics and 1977 reemergence of H1N1. Each circle represents a geometric mean antibody titer in serum from a single individual from two independent replicates. Samples from adults are grey and children are blue. Trend lines are locally estimated scatterplot smoothing (LOESS) curves (smoothing parameter = 0.4, degree = 2) with 95% CIs, fitted to adult samples.
