■各国建议对青春期少女常规接种一到两剂人乳头瘤病毒(HPV)疫苗,以消除宫颈癌这一公共卫生问题。由于大多数现有疫苗剂量被现有HPV疫苗接种计划的国家(主要是高收入国家)吸收,有限的供应一直留给新的国家引进,直到2022年;其中许多,低收入和中等收入国家死亡率较高。免疫战略专家咨询小组考虑了几种疫苗接种战略,以允许更多国家在供应有限的情况下引入疫苗接种。
■我们研究了从2020年到2030年向100个引进前国家分配有限疫苗剂量的九种策略的影响。使用两种算法来优化癌症死亡的总数,通过有限的剂量(背包和国家特定死亡率的递减顺序)可以避免全球范围内的癌症死亡总数。并使用了未优化的算法(人类发展指数的降序)。
■定期给14岁的女孩接种一剂或两剂疫苗,并在供应不再受限的情况下转向常规的9岁计划,可以防止大多数宫颈癌死亡,不管分配算法。未优化的分配避免了更少的死亡,因为它首先分配给高收入国家,通常具有较低的子宫颈癌死亡率。
■为了在供应有限的情况下优化通过疫苗接种避免的死亡,重要的是优先考虑高负担国家,并首先为年龄较大的女孩接种疫苗。
■谁,比尔和梅林达·盖茨基金会。
UNASSIGNED: Countries are recommended to immunise adolescent girls routinely with one or two doses of human papillomavirus (HPV) vaccines to eliminate cervical cancer as a public health problem. With most existing vaccine doses absorbed by countries (mostly high-income) with existing HPV vaccination programmes, limited supply has been left for new country introductions until 2022; many of those, low- and middle-income countries with higher mortality. Several vaccination strategies were considered by the Strategic Advisory Group of Experts on Immunization to allow more countries to introduce vaccination despite constrained supplies.
UNASSIGNED: We examined the impact of nine strategies for allocating limited vaccine doses to 100 pre-introduction countries from 2020 to 2030. Two algorithms were used to optimise the total number of cancer deaths that can be averted worldwide by a limited number of doses (knapsack and decreasing order of country-specific mortality rates), and an unoptimised algorithm (decreasing order of Human Development Index) were used.
UNASSIGNED: Routinely vaccinating 14-year-old girls with either one or two doses and switching to a routine 9-year-old programme when supply is no longer constrained could prevent the most cervical cancer deaths, regardless of allocation algorithm. The unoptimised allocation averts fewer deaths because it allocates first to higher-income countries, usually with lower cervical cancer mortality.
UNASSIGNED: To optimise the deaths averted through vaccination when supply is limited, it is important to prioritise high-burden countries and vaccinating older girls first.
UNASSIGNED: WHO, Bill & Melinda Gates Foundation.