Effectiveness and cost-effectiveness of human papillomavirus vaccination strategies among men who have sex with men in China: a modeling study.

Introduction: The health and economic benefits of human papillomavirus (HPV) vaccination targeted at men who have sex with men (MSM) in developing settings have been rarely assessed. This study aimed to evaluate the effectiveness and cost-effectiveness of different HPV vaccination strategies among MSM in China. Methods: A Markov model was developed to simulate HPV transmission dynamics among a total of 30.73 million MSM in China. The corresponding natural history included 6 states: susceptible, infected with low-risk subtypes, high-risk subtypes, anogenital warts and anal cancer, and deaths from anal cancer. MSM were divided into three age groups with cut-off points of 27 and 45 years. Alternative vaccination strategies were built by allocating bivalent, quadrivalent, nine-valent, or no vaccine to each of the groups. We generated the prevented infections and deaths by vaccination compared with baseline (no vaccination) and calculated incremental cost-effectiveness ratios (ICERs) to determine the optimal strategy. Results: The model showed that in 10 years, at baseline, the existing cases of anogenital warts would reach 5,464,225 (IQR, 4,685,708-6,174,175); that of anal cancer would reach 1,922.95 (1,716.56-2,119.93), resulting in 940.55 (732.27-1,141.87) deaths. Under 50% vaccination coverage among one age group, the prevented cases of anogenital warts were maximized with quadrivalent vaccines allocated to MSM aged 27-45 years; that of anal cancer were maximized when offering nine-valent vaccines to the same group. Under 50% vaccination coverage among all groups, the lowest ICER (34,098.09 USD/QALY, 31,146.54-37,062.88) was reached when only quadrivalent vaccines were provided. Based on this strategy, when the annual vaccination rate increased by 30%, the ICER (33,521.75 USD/QALY, 31,040.73-36,013.92) would fall below three times China's per capita GDP. When the vaccine price decreased by 60%, the ICER was reduced to 7,344.44 USD/QALY (4,392.89-10,309.23), indicating good cost-effectiveness taking China's per capita GDP as a threshold. Conclusions: HPV vaccination can effectively reduce the prevalence and mortality of related diseases among MSM in China, especially quadrivalent vaccines for anogenital warts and nine-valent vaccines for anal cancer. MSM aged 27-45 years were the optimal group for vaccination. Annual vaccination and appropriate adjustment of vaccine price are necessary to further improve the cost-effectiveness.

Refined assessment of size-fractioned particulate matter (PM2.5/PM10/PMtotal) emissions from coal-fired power plants in China.

Chinese coal-fired power plants (CFPPs) are experiencing large-scale and rapid retrofitting of ultralow emission (ULE), causing significant changes in emission level of particulate matter (PM) from CFPPs. In this study, based on coal ash mass balance over the whole process, an integrated emission factors (EFs) database of three size-fractioned particulate matters (PM2.5, PM10, and PMtotal) for CFPPs is constructed, which covers almost all typical ULE technical routes installed in CFPPs. To verify the reliability of PM EFs established in this study, we compare those with related results based on field tests. Overall, the gaps in the EFs of PM2.5, PM10, and PMtotal obtained by the two methods are not outrageous within a reasonable range. By combined with the refined size-fractioned PM EFs and unit-based activity level database, a detailed high-resolution emission inventory of PM2.5, PM10, and PMtotal from Chinese CFPPs in 2017 is established, with the corresponding total emissions of 143, 207, and 267 kt, respectively. Our estimation of PMtotal emission is comparable to the official statistics announced by China Electricity Council (CEC), which further demonstrates the reliability of PM EFs constructed in this study. Moreover, potential reductions of PM from CFPPs at two stages before and after 2017 are assessed under three application scenarios of major ULE technical routes. We forecast the final annual emissions of PM2.5, PM10, and PMtotal until 2020 will be reduced further, which fall within the range of 86-111 kt, 120-157 kt, and 142-184 kt, respectively, if all CFPPs achieve ULE requirements under the three scenarios. We believe our integrated database of PM EFs of CFPPs has good universality, and the forecast results will be helpful for policy guidance of ULE technologies, emissions inventory compilation, and regional air quality simulation and management.