Fig. 2. Omicron BA.1 and BA.2 breakthrough infection rapidly recalls neutralizing antibodies that are broad and durable.
(A) Kinetics of plasma neutralization activity following breakthrough infection against ancestral VIC01 or matched infecting Omicron BA.1 and BA.2 strains. Thick lines represent the mean estimate from the piecewise linear regression model using the estimated parameters. Plasma neutralization activity was measured using a live virus neutralization assay against SARS-CoV-2 clinical isolates in human embryonic kidney–293T cells transduced with ACE2 and TMPRSS2. (B) Neutralization mediated by BA.1 and BA.2 breakthrough plasma against ancestral VIC01, Omicron BA.1, BA.2, BA.4, XBB, and BQ.1.1 strains at a median of 34 days after symptom onset. Data are presented as fold change in neutralization IC50 (variant/ancestral), with lines and error bars depicting median ± IQR, and fold drop in neutralization IC50 from ancestral virus shown above each variant. (C) Longitudinal decay kinetics of plasma neutralization activity following breakthrough infection against ancestral VIC01 or matched infecting Omicron BA.1 or BA.2 strains up to 4 to 7 months after symptom onset. The best fit decay slopes (thick lines) are depicted. (D) IgG antibody endpoint titers against BA.1 spike for BA.1 breakthrough subjects (red) and against BA.2 spike for BA.2 breakthrough subjects (blue) following preincubation with BSA control (closed circles) or ancestral Wuhan-hu-1 spike (open circles). D30, day 30.