Fig. 4.

Relationship of epithelial thickness and susceptibility to SHIV infection A. The graph shows the percentage of 43 female pigtail macaques with est. (=estimated) SHIV acquisition time point at the indicated menstrual cycle segments of four days. The macaques became SHIVSF162P3 infected after repeated vaginal exposure at low virus dose, as published ²⁴. Data were analyzed and plotted for 4-day intervals. B, C: Scatter plots of the thickness of mean vaginal epithelial layers during 4-day menstrual cycle segments, and the estimated SHIV acquisition in corresponding 4-day segments in 43 different macaques. The line represent linear regression analysis; R = Pearson co-efficient; p-value results from hypothesis test of non-zero slope. The right Y axis refers to the number of infections as reported in ²⁴. D. Smoothed data were graphed to further examine the relationship of non-nucleated layer thickness and susceptibility to infection throughout the menstrual cycle.