Figure 4.

Lower vaccine-induced anti-RBD antibody titers are associated with the development of SARS-CoV-2 BTI. Anti-RBD antibody titers against the Wuhan, Gamma, Mu, and Delta variants were measured at 15-30 days after the second BNT162b2 vaccine dose in individuals with or without a history of BTI (n=21). BTI were determined by clinical records or seroconversion in nucleoprotein antibodies measured 6-8 months after the second vaccine dose. Each circle represents an individual sample. The height of the bars and the numbers over them indicate the geometric mean titer. The 95% CI is also shown. The Mann-Whitney test was performed. The dotted line represents the limit of detection of the assay. ns, Not statistically significant; BTI, Breakthrough infection. *p-value <0.05; **p-value <0.01.