Figure 1.

Conceptual diagram illustrating the effect of a prophylactic vaccine on HSV-2 acquisition. VE_S is defined as the proportional reduction in the susceptibility to infection among those vaccinated relative to those unvaccinated. Asymptomatic genital HSV-2 infection was defined as a person who is HSV-2 seropositive but never develops significant symptoms to warrant medical intervention, whereas symptomatic genital HSV-2 infection refers to an HSV-2 seropositive person who develops symptoms that may warrant medical intervention. In this figure, solid lines denote progression or forward movement from one population compartment to the next, while dashed lines denote backward movement from the present population compartment to the previous population compartment.