Fig. 7: Peak antibody and cellular response after third vaccine do not correlate with protection against breakthrough.

a, Kaplan–Meier curve showing the probability of infection from third vaccine in recipients who had follow-up screening after vaccination. Follow-up time began 7 d after the third vaccine (n = 305, 81 positive PCR or LFD). The 95% confidence intervals (CIs) are shown in a lighter shade. b, Kaplan–Meier curve showing the probability of infection from third vaccine in recipients stratified by <65 and ≥65 years of age. Follow-up time began 7 d after the third vaccine (blue, <65 years, 54 positive test; green, ≥65 years, 27 positive test, n = 305, log-rank P = 0.099). The 95% CIs are shown in a lighter shade. c, Kaplan–Meier curve of the probability of infection in relation to spike-specific antibody response above predicted (green) or below predicted (red) median over the subsequent 120 d. Cox proportional hazards regression model: hazard ratio, 0.96 (95% CI 0.45–2.06, P = 0.93), n = 122 participants. d, Kaplan–Meier curve of the probability of infection in relation to spike-specific cellular response above (green) or below (red) predicted median over the subsequent 120 d. Cox proportional hazards regression model: hazard ratio, 0.81 (95% CI 0.37–1.74, P = 0.59), n = 122 participants.