Fig. 3. Kaplan–Meier survival curves of risk of symptomatic breakthrough infection or hospitalization according to post-third vaccination anti-spike IgG levels. (A) When the patients were regrouped according to an anti-spike IgG level of 400 AU/mL (determined based on a ROC curve; data not shown), the risk of developing symptomatic breakthrough infection differed significantly between the groups (log-rank test, P< 0.0001). (B) When the patients were regrouped according to an anti-RBD IgG level of 200 AU/mL (determined based on a ROC curve; data not shown), the risk of hospitalization was higher in patients with anti-RBD IgG <200 AU/mL than in patients with anti-RBD IgG ≥200 AU/mL (log-rank test, P<0.0001).
Abbreviation: RBD, receptor-binding domain.

Ann Lab Med 2024;44:64~73 https://doi.org/10.3343/alm.2024.44.1.64