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Figure 1: (A) Evolution of neutralizing antibodies against the BA.5 omicron variant before and after the bivalent booster with a 6‐month follow‐up in a population of 51 healthy-volunteers. GMT were 157 (95% CI: 112–219), 598 (470–761), 1,095 (903–1,327), 106 (83.4–134), and 47.4 (36.6–61.6) at baseline and after 14, 28, 90, and 180 days. (B ) Kinetic models of the neutralizing capacity against the BA.5 omicron variant. (C ) Comparison of the neutralizing capacity against the D614G strain, the delta and BA.5 omicron variants, and the XBB.1.5 omicron subvariant in a population of 30 healthy-volunteers 6 months after having received the bivalent booster. GMT were 319 (95% CI: 241–423), 162 (119–220), 61.4 (42.7–88.2), and 29.5 (21.4–40.6) for the D614G strain, the delta variant, the BA.5 omicron variant, and the XBB.1.5 omicron subvariant. The dotted line represents the positivity cut‐off for neutralizing antibodies (dilution titer of 1:20). (D ) Evolution of the cellular response by means of the measurement of IFNγ. GMT were 0.53 UI/mL (95% CI: 0.37–0.75), 0.95 (0.72–1.24), 0.87 (0.65–1.17), 0.65 (0.48–0.87), and 0.52 (0.34–0.79) at baseline and after 14, 28, 90, and 180 days. The positivity cut‐off for IFNγ was 0.013 IU/mL. Geometric means and 95% CIs are represented. Only p values <0.05 were graphically represented.