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. 2023 Mar 11;8:36. doi: 10.1038/s41541-023-00630-0

Fig. 4. Analyses of D57 antibody markers as a correlate of risk in baseline SARS-CoV-2 negative vaccine recipients.

Fig. 4

a, b Age and baseline risk score-adjusted cumulative incidence of COVID-19 by 92 days post D57 by D57 (A) anti-spike IgG or (b) pseudovirus (PsV)-nAb ID50 titer, estimated using a marginalized Cox model. The dotted black lines indicate bootstrap pointwise 95% CIs. The upper and lower horizontal gray lines are the overall cumulative incidence of COVID-19 from 7 to 92 days post D57 in placebo and vaccine recipients, respectively. Curves are plotted over the antibody marker range from the 2.5th percentile to the 97.5th percentile: 21.3 to 1088 BAU/ml for spike IgG and 1.31 to 270 IU50/ml for PsV-nAb ID50. c, d Age and baseline risk score-adjusted cumulative incidence of COVID-19 by 92 days post D57 by D57 (c) anti-spike IgG or (d) PsV-nAb ID50 titer above a threshold. The blue dots are point estimates at each COVID-19 primary endpoint linearly interpolated by solid black lines; the gray shaded area is pointwise 95% confidence intervals (CIs). The estimates and CIs assume a non-increasing threshold-response function. The upper boundary of the green shaded area is the estimate of the reverse cumulative distribution function (CDF) of D57 antibody marker level. The vertical red dashed line is the D57 antibody marker threshold above which no COVID-19 endpoints occurred (in the time frame of 7 days post D57 through to the data cut-off date March 5, 2021). PsV, pseudovirus.