Fig. 2: SARS-CoV-2 spike-binding antibody responses and SARS-CoV-2 spike-specific memory B cells in blood following vaccination with BNT162b2.

a, Total anti-spike IgG and subclasses after first and second doses of vaccine and in individuals with prior COVID-19. MFI, mean fluorescence intensity. b, Pearson’s correlation (r) between anti-spike IgG binding antibody responses after first dose and age (n = 134). c, Pearson’s correlation between anti-spike IgG (n = 134) binding antibody responses and neutralization by sera against SARS-CoV-2 in a spike lentiviral pseudotyping assay expressing wild-type spike (D614G). d, Anti-spike IgG subclass responses to first dose vaccine stratified by age (<80 and ≥80 years). e, CD19⁺ memory B cells (left, as percentage of PBMCs) and SARS-CoV-2 spike-specific CD19⁺IgG⁺IgM⁻ memory B cells (right, as percentage of all memory B cells) from FACS-sorted PBMCs. n = 16 for ≥80 years, n = 16 for <80 years; stratified by neutralizing response after first dose, n = 8 in each category. MFI – mean fluorescence intensity. Mann–Whitney test was used for unpaired comparisons. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; NS, not significant. Scatter plots show linear correlation line bounded by 95% CI; β, slope/regression coefficient. Error bars, s.d.