Incidence of chronic HCV infection (ppy) after the introduction of a hypothetical HCV vaccine, by targeting strategy: A. no targeting, B. risk targeting, and C. sero-targeting, efficacy, and vaccination rate over time. Figures show the mean of 100 realizations. Standard deviations 30 years after vaccine introduction range from 0.006 (for lower incidence) to 0.019 (for higher incidence).