Fig. 1: Humoral immune imprinting in mice.
From: Repeated Omicron exposures override ancestral SARS-CoV-2 immune imprinting
a, NAb response after two doses of priming with CoronaVac followed by boosting with SARS-CoV-1 spike protein or SARS-CoV-2 variant spike proteins in mice. b, NAb response after 2 doses of CoronaVac priming followed by boosting with variant spike proteins with 3-month (mo) or 6-month time intervals in mice. a,b, The x-axis labels indicate NT50 values against the respective variants and the variants used for boosting are indicated at the bottom of the figure; fold differences in titres against variants compared with D614G are shown above the line. c, NAb response after priming with 2 doses of variant spike proteins or priming with 2 doses of CoronaVac followed by 2 boosts of variant spike proteins with 1-month or 3-month intervals in mice. d, NAb response after priming with two doses of variant spike mRNAs or priming with two doses of CoronaVac followed by two boosts of variant spike mRNAs. c,d, The variants used for priming or boosting are indicated at the bottom of the figure and red, blue, yellow circles indicate NT50 values for BA.5, BQ.1.1 and XBB. Ten mice were immunized and analysed in each group (n = 10) except in b eight mice were immunized with BA.5 booster 6 months after priming (n = 8). The dosage of CoronaVac, spike protein and spike mRNA were 3 μg, 10 μg and 1 μg, respectively. Sera were collected four weeks after the last dose. Geometric mean titres (GMTs) are shown. Two-tailed Wilcoxon signed-rank tests for paired samples in a,b and two-tailed Wilcoxon rank-sum tests for independent samples in c,d. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; NS, not significant (P > 0.05). All neutralization assays were conducted as at least two independent experiments.
