Fig. 1
Stronger humoral immune responses against the Delta SARS-CoV-2 variant following heterologous ChAdOx1 nCoV-19 (ChAd)/BNT162b2 (BNT) than homologous ChAd/ChAd vaccination. a Reciprocal titers of neutralizing antibodies against the Delta SARS-CoV-2-S variant measured using a surrogate virus neutralization test (sVNT). Data are from n = 31 biologically independent samples from the ChAd/ChAd group and n = 54 biologically independent samples from the ChAd/BNT group. b Reciprocal titers of neutralizing antibodies against the Delta SARS-CoV-2 variant measured using a surrogate virus neutralization test (sVNT). Data are from n = 30 biologically independent samples from BNT/BNT. c Efficacies of antibody neutralization against the SARS-CoV-2 Delta variant measured by surrogate virus neutralization tests (sVNT) show a strong positive correlation with those of pseudotyped virus neutralization tests (pVNT). Correlation (solid line) and 95% confidence intervals (dotted lines) between sVNT1:180 and antibody titers resulting in a 50% reduction in luciferase activity in pVNT, indicated as pVNT50. Open circles, values from individual donors, and outliers are marked with X and were defined as values with absolute residual value >2 SD of all residual values in each group of samples. Correlation was calculated using simple linear regression. a, b Chi-square test for trend; dots represent individual vaccinees, lines represent group median. Open symbols: preboost sera, filled symbols: postboost sera. For better visualization of identical titer values, data were randomly and proportionally adjusted closely around the precise titer result
