Fig. 4

Strain-specific and anti-receptor-binding-site antibodies select mutations with large antigenic effects, but anti-stalk antibodies only select small-effect mutations. The excess fraction of virions with a mutation at each site that survive the antibody, averaging across all amino-acid mutations at each site (see Eq. 10). There are multiple sites of large-effect mutations for H17-L19, H17-L10, H17-L7, and S139/1, but none for FI6v3 and C179. Supplementary Fig. 2 shows the excess fraction surviving for the largest-effect mutation at each site. Supplementary Figs. 3, 4, 5, 6, 7, and 8. show all mutations using logo plots. Sites are labeled in H3 numbering