Durham David P, Ndeffo-Mbah Martial L, Skrip Laura A, Jones Forrest K, Bauch Chris T, Galvani Alison P
Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, Yale University, New Haven, CT 06511;
Department of Applied Mathematics, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Proc Natl Acad Sci U S A. 2016 May 3;113(18):5107-12. doi: 10.1073/pnas.1515528113. Epub 2016 Apr 18.
Every year in the United States more than 12,000 women are diagnosed with cervical cancer, a disease principally caused by human papillomavirus (HPV). Bivalent and quadrivalent HPV vaccines protect against 66% of HPV-associated cervical cancers, and a new nonavalent vaccine protects against an additional 15% of cervical cancers. However, vaccination policy varies across states, and migration between states interdependently dilutes state-specific vaccination policies. To quantify the economic and epidemiological impacts of switching to the nonavalent vaccine both for individual states and for the nation as a whole, we developed a model of HPV transmission and cervical cancer incidence that incorporates state-specific demographic dynamics, sexual behavior, and migratory patterns. At the national level, the nonavalent vaccine was shown to be cost-effective compared with the bivalent and quadrivalent vaccines at any coverage despite the greater per-dose cost of the new vaccine. Furthermore, the nonavalent vaccine remains cost-effective with up to an additional 40% coverage of the adolescent population, representing 80% of girls and 62% of boys. We find that expansion of coverage would have the greatest health impact in states with the lowest coverage because of the decreasing marginal returns of herd immunity. Our results show that if policies promoting nonavalent vaccine implementation and expansion of coverage are coordinated across multiple states, all states benefit both in health and in economic terms.
在美国，每年有超过1.2万名女性被诊断出患有宫颈癌，这种疾病主要由人乳头瘤病毒（HPV）引起。二价和四价HPV疫苗可预防66%的HPV相关宫颈癌，而一种新的九价疫苗可额外预防15%的宫颈癌。然而，各州的疫苗接种政策各不相同，州与州之间的人口迁移相互影响，削弱了各州特定的疫苗接种政策。为了量化转向九价疫苗对各个州以及整个国家的经济和流行病学影响，我们建立了一个HPV传播和宫颈癌发病率模型，该模型纳入了各州特定的人口动态、性行为和迁徙模式。在国家层面，尽管新疫苗的单剂量成本更高，但在任何覆盖率下，九价疫苗与二价和四价疫苗相比都具有成本效益。此外，九价疫苗在青少年人群覆盖率额外提高40%（即80%的女孩和62%的男孩）的情况下仍具有成本效益。我们发现，由于群体免疫的边际效益递减，扩大覆盖率对覆盖率最低的州的健康影响最大。我们的结果表明，如果在多个州协调促进九价疫苗实施和扩大覆盖率的政策，所有州在健康和经济方面都会受益。
