Fig. 3: Antibody and T-cell responses in vaccinated healthcare workers with or without SARS-CoV-2 breakthrough infections.

a Anti-spike IgG level (AU: arbitrary units); b serum neutralizing titer; c IFNγ-producing spot forming cells (SFC)/106 peripheral blood mononuclear cells (PBMC). Immune response was determined within 48 h after diagnosis in infected subjects, and 21 days after complete vaccination schedule in non-infected subjects. Median values with interquartile ranges are shown. Mann–Whitney U-test (two-sided) was used for statistical analysis.