Figure 1

The filled circles are the averages for groups of 60 mice for each viral dose. The curve is the best fit of the Michaelis-Menten relationship, f = 1/(1 + dose^-1), for the dose response data. The black square shows that 50% of animals treated with GML in KYWJ became infected with a viral dose of 0.1 ID₅₀, and the dashed arrow indicates that this treatment caused a 10-fold increase in susceptibility (see Table 2).