Effect of modeling assumptions on projected impact of vaccination.

The base-case estimates of ultimate reductions in anal HPV16 infection prevalence among MSM by vaccination scenario. Data are summarized as Tukey boxplots (i.e., interquartile range [IQR], with whiskers extending to at most 1.5 times IQR from the box, and outliers shown separately) according to presumed natural history (upper panels; models ordered as in Table 2) and sexual contact structure (lower panels) of the models included in predictions. The various sexual contact structures are grouped according to sexual activity distribution, assortative mixing with respect to sexual activity, and assortative mixing with respect to preference for insertive/receptive anal sex. Note the differences in scale for the vaccination scenarios. HPV16, human papillomavirus genotype 16; MSM, men who have sex with men; SIS, susceptible-infected-susceptible model.