Bagamian Scientific Consulting, Gainesville, FL, USA; Health Affairs Institute, West Virginia University, Morgantown, WV, USA.
Bagamian Scientific Consulting, Gainesville, FL, USA; Department of Environmental and Global Health, University of Florida, Gainesville, FL, USA.
Lancet Glob Health. 2023 Jun;11(6):e880-e891. doi: 10.1016/S2214-109X(23)00192-4.
Vaccine impact and cost-effectiveness models have mostly focused on acute burden. Shigella-attributable moderate-to-severe diarrhoea has been shown to be associated with childhood linear growth faltering. Evidence also links less severe diarrhoea to linear growth faltering. As Shigella vaccines are in late stages of clinical development, we aimed to estimate the potential impact and cost-effectiveness of vaccination against Shigella burden that includes stunting and the acute burden attributable to less severe diarrhoea and moderate-to-severe diarrhoea.
We used a simulation model to estimate Shigella burden and potential vaccination in children aged 5 years or younger from 102 low-income to middle-income countries from 2025 to 2044. Our model included stunting associated with Shigella-related moderate-to-severe diarrhoea and less severe diarrhoea and we explored vaccination impact on health and economic outcomes.
We estimate 109 million (95% uncertainty interval [UI] 39-204) Shigella-attributable stunting cases and 1·4 million (0·8-2·1) deaths in unvaccinated children over 20 years. We project that Shigella vaccination could avert 43 million (13-92) stunting cases and 590 000 (297 000-983 000) deaths over 20 years. The overall mean incremental cost-effectiveness ratio (ICER) was US$849 (95% uncertainty interval 423-1575; median $790 [IQR 635-1005]) per disability-adjusted life-year averted. Vaccination was most cost-effective in the WHO African region and in low-income countries. Including the burden of Shigella-related less severe diarrhoea improved mean ICERs by 47-48% for these groups and substantially improved ICERs for other regions.
Our model suggests that Shigella vaccination would be a cost-effective intervention, with a substantial impact in specific countries and regions. Other regions could potentially benefit upon the inclusion of the burden of Shigella-related stunting and less severe diarrhoea in the analysis.
Bill & Melinda Gates Foundation and Wellcome Trust.
疫苗的影响和成本效益模型主要集中在急性负担上。已有研究表明，志贺菌引起的中重度腹泻与儿童线性生长发育迟缓有关。证据还表明，较轻的腹泻也与线性生长发育迟缓有关。由于志贺菌疫苗正处于临床开发的后期阶段，我们旨在评估针对志贺菌负担（包括发育迟缓以及由较轻腹泻和中重度腹泻引起的急性负担）进行疫苗接种的潜在影响和成本效益。
我们使用模拟模型来估计 2025 年至 2044 年期间来自 102 个中低收入国家的 5 岁及以下儿童的志贺菌负担和潜在疫苗接种情况。我们的模型包括与志贺菌相关的中重度腹泻和较轻腹泻相关的发育迟缓，并探讨了疫苗接种对健康和经济结果的影响。
我们估计在未接种疫苗的儿童中，20 年内有 1.09 亿例（95%置信区间[UI]为 3900 万至 2.04 亿）与志贺菌相关的发育迟缓病例和 14 万（8 万至 21 万）例死亡。我们预计志贺菌疫苗接种可以在 20 年内预防 4300 万例（1300 万至 9200 万）发育迟缓病例和 59 万（29.7 万至 98.3 万）例死亡。总体平均增量成本效益比（ICER）为每避免一个残疾调整生命年（DALY）849 美元（95%置信区间为 423 美元至 1575 美元；中位数为 790 美元[IQR 635 美元至 1005 美元]）。在世界卫生组织非洲区域和低收入国家，疫苗接种的成本效益最高。在这些地区，将志贺菌相关较轻腹泻的负担纳入分析，平均 ICER 提高了 47%至 48%。
我们的模型表明，志贺菌疫苗接种将是一种具有成本效益的干预措施，在特定国家和地区具有重大影响。其他地区可能会从将志贺菌相关发育迟缓与较轻腹泻的负担纳入分析中受益。
比尔及梅琳达·盖茨基金会和惠康信托基金会。
