Figure 1

Estimated probability of infection given the dose of brain homogenate used in the study. The probability of infection given the dose S(d) could be expressed as: S(d) = exp(−3.01+1.12*d)/(1+exp(−3.01+1.12*d)), which results in the updated graph displayed as continuous line. For comparison, the previous graph based on interim data is displayed as dotted line, as published in 2007 [1].