Figure 6.
Probit regression analysis relating NAb titers at the time of virus challenge and probability of protection. The black circles denote SHIVAD8EO challenged monkeys; the red circles denote SHIVDH12-V3AD8 challenged monkeys. Horizontal lines indicate 90% confidence intervals of plasma neutralization titers for 33, 50, 80, 90, and 95% probability of protection. The estimated neutralization titers in plasma conferring different levels of protection and their corresponding 90% confidence intervals are shown at the bottom of the figure.