Figure 3.
Neutralization titers (ID50 values) against variant pseudoviruses from post-vaccination sera with and without post-vaccination infection (PVI)
(A–G) Sera are from individuals who received (A) two doses of an mRNA COVID-19 vaccine or (B) three doses of an mRNA COVID-19 vaccine. Serum samples were obtained about 5–6 weeks following the last vaccine dose. PVI neutralization titers after 2 doses of wild-type mRNA COVID-19 vaccine in individuals infected with the (C) pre-Delta wave (Alpha or Gamma or others), (D and E) Delta, or (F and G) Omicron (BA.1 or BA.1.1) variants. Each gray line corresponds to one serum sample. GMT is listed for each variant. Significance values for each antigen are shown relative to the titer against D614G. Two of the Delta wave PVI serum samples in (D) were measured at multiple time points, shown in (E), from 1 month after the second vaccine dose and 1 month before and after PVI. (F) Shows titers from individuals with an Omicron (BA.1 or BA.1.1) PVI 2–10 months after the second vaccine, whereas (G) shows titers from individuals with an Omicron (BA.1 or BA.1.1) PVI 1–5 months after the third vaccine.
(H) The GMT of individual variants after vaccination with or without PVI by timeline. For all neutralization assays, the serum was diluted 1:40 followed by 3-fold serial dilutions. Neutralization assays were performed twice, each with an intra-assay duplicate. Neutralization curves were fitted using nonlinear dose-response regression. Titers measuring below the lowest serum dilution of 1:40 were treated as 20 for statistical analysis. Statistical analysis was performed on the paired samples using the Friedman test, followed by post hoc Dunn’s multiple comparison tests. p values for comparisons between the groups are shown, where ∗p ≤ 0.05, ∗∗p ≤ 0.01, ∗∗∗p ≤ 0.001, and ∗∗∗∗p ≤ 0.0001. NS, no significance; vx, vaccine. Pie charts indicate the percent of serum samples above the lowest tested (1:40). Numbers in parentheses indicate fold reduction in titer relative to D614G.