Fig. 4: Distributions of VRC01 serum PT₈₀ against viruses acquired by placebo recipients, within each virus neutralization IC₈₀ sensitivity category.

Approach 2 of Huang et al.¹¹ was used to calculate PT₈₀ against a given virus, by dividing the popPK model-predicted VRC01 serum concentration by the IC₈₀ of the VRC01 drug product against the virus. The distributions are for PT₈₀ values of the 82 noncases in the case-control cohort calculated each day over the 80-week follow-up against each of the viruses (n = 19 IC₈₀ < 1 µg ml^–1; n = 10 IC₈₀ 1–3 µg ml^–1; n = 35 IC₈₀ > 3 µg ml^–1) acquired by placebo recipients. On the y axis, each filled black dot is a point estimate of PE against viruses in the specified sensitivity category and vertical lines are 95% CI estimates as previously reported⁶. The arrow indicates a value (−108.7) below the y-axis lower limit. On the x axis, each filled black dot is the median PT₈₀ against viruses acquired by placebo recipients within each virus neutralization IC₈₀ sensitivity category; horizontal rectangles extend through the interquartile range, and on each side of the boxplot is a kernel density estimation of the distribution shape of PT₈₀.