Fig. 1

Neutralizing profiles of naive and breakthrough infection with Delta, Omicron BA.1, and BA.2 variants. a–c ID₅₀ against Delta, BA.1, BA.2, and BA.4/5 variants of samples from naive infections with Delta (a), BA.1 (b), and BA.2 (c) variant. d–f ID₅₀ against Delta, BA.1, BA.2, and BA.4/5 variants of samples from breakthrough infections with Delta (d), BA.1 (e), and BA.2 (f) variant in regular vaccinees. g, h ID₅₀ against Delta, BA.1, BA.2, and BA.4/5 variants of samples from breakthrough infections with BA.1 (g) and BA.2 (h) variant in booster vaccinees. For all panels, values above the symbols denote geometric mean titers, and the numbers in parentheses denote the proportion of positive plasma with ID₅₀ above the limit of detection (dotted lines, ≥1:20). Values above the transverse lines denote fold changes and p values. Statistical significance was determined using Mann–Whitney U-test, and p values less than 0.05 were considered statistically significant