Fig. 5

Antigenic map of serum virus neutralization data. Antigenic maps were generated via the Racmacs program (1.1.4) on the basis of neutralization titers against the indicated pseudoviruses. a, c Maps derived from all vaccine cohorts after vaccination. b Maps of SARS-CoV-2-uninfected older adults at days 21, 92, and 185 after receiving the Tri‑XBB.1.5 vaccine, Bi‑Omi‑XBB vaccine, or Tetra‑XBB.1 vaccine, during six months of follow-up. d Maps of SARS-CoV-2-infected older adults 92 or 185 days after receiving booster vaccination during six months of follow-up. In each map, circles represent the indicated variants, and squares denote individual serum samples. Both the x- and y-axes are in antigenic units (AUs), where one grid corresponds to a 2-fold serum dilution of the neutralization titer. One square corresponds to one AU squared. Arrows between D614G and selected variants indicate the antigenic distance in AUs