Widespread implementation of prophylactic human papillomavirus (HPV) vaccines could substantially decrease morbidity and mortality from cervical cancer and other HPV-related diseases. Information about epidemiologic trends in HPV after vaccine introduction in community settings is essential in order to assess the progress and population impact of HPV immunization programs, and to provide data for programmatic and policy decisions. Thus, we conducted pilot HPV surveillance studies among ~800 13-26 year-old young women, before (2007;none vaccinated) and three years after (2010;59% vaccinated) widespread vaccine introduction in a community. We found: 1) a substantial decline in vaccine-type HPV prevalence among all women (58%), 2) evidence for herd protection (i.e. a decline of 49% in vaccine-type HPV among unvaccinated women), and 3) possible evidence for type-replacement (i.e. an increase of 25% in the prevalence of non- vaccine-type HPV among vaccinated women). The overall objective of this proposal is to further characterize the community-level impact of HPV vaccine introduction, in men as well as women, by determining changes in vaccine-type HPV, characterizing herd protection, and investigating possible type replacement during the first nine years after HPV vaccine introduction. We will pursue the following three specific aims: (1) Determine trends in vaccine-type HPV prevalence among young women and men to a) assess the epidemiologic impact of HPV vaccine introduction in the community, and b) explore changes in the prevalence of genetically-related HPV types;(2) Determine trends in vaccine-type HPV prevalence among unvaccinated young women and men, in order to a) characterize and b) examine mechanisms for herd protection after vaccine introduction in the community;and (3) Determine trends in non-vaccine-type HPV prevalence among vaccinated and unvaccinated young women and men, in order to a) investigate and b) examine alternative (e.g. statistical) explanations for HPV type-replacement. We plan to accomplish the overall objective using the following approach: we will enroll diverse samples of 13-26 year-old women (N=400) and men (N=400) in two additional surveillance studies (total N=1600), and examine vaccination rates and HPV prevalence at all four time points in women (2007, 2010, 2013, and 2016) and two time points in men (2013 and 2016). The proposed research is innovative because 1) it is the first study to provide empirical data concerning changes in vaccine-type HPV, herd protection, and type replacement during the first nine years after HPV vaccine introduction in both men and women;2) the data could shift current research and clinical practice paradigms in vaccine development;and 3) the research plan utilizes novel concepts, approaches and methodologies to explore mechanisms of herd protection and type-replacement. The proposed research is significant, because it will help to characterize the community-level impact of HPV immunization programs and provide data that are essential for programmatic and policy decisions to maximize the public health impact of HPV vaccination.
Characterizing the epidemiologic impact of HPV vaccine introduction in men and women is an important but under-investigated area of virology and epidemiology that has direct implications for maximizing the public health benefit of HPV vaccines. The results of this study are expected to guide future vaccine development as well as decisions about vaccine delivery, policies and programs that will maximize the effectiveness of vaccination in decreasing rates of cervical cancer and other HPV-related cancers. This proposal addresses several objectives of Healthy People 2020, including reducing the proportion of females with HPV infection and reducing the death rate from cervical cancer.
|Smith, C; Ding, L; Gorbach, P M et al. (2018) Who's Not Protected in the Herd? Factors Associated with Vaccine-Type HPV in Unvaccinated Women. J Pediatr Adolesc Gynecol 31:89-93|
|Chandler, Emmanuel; Ding, Lili; Gorbach, Pamina et al. (2018) Epidemiology of Any and Vaccine-Type Anogenital Human Papillomavirus Among 13-26-Year-Old Young Men After HPV Vaccine Introduction. J Adolesc Health 63:43-49|
|Morrow, Charlene; Thomas, Rachel; Ding, Lili et al. (2018) Prevalence of potential sexual abuse in adolescents and young adults and feasibility of an assessment and management plan used in three research projects. Res Nurs Health 41:166-172|
|Thomas, Rachel; Higgins, Lisa; Ding, Lili et al. (2018) Factors Associated With HPV Vaccine Initiation, Vaccine Completion, and Accuracy of Self-Reported Vaccination Status Among 13- to 26-Year-Old Men. Am J Mens Health 12:819-827|
|Ding, Lili; Widdice, Lea E; Kahn, Jessica A (2017) Differences between vaccinated and unvaccinated women explain increase in non-vaccine-type human papillomavirus in unvaccinated women after vaccine introduction. Vaccine 35:7217-7221|
|Kahn, Jessica A; Widdice, Lea E; Ding, Lili et al. (2016) Substantial Decline in Vaccine-Type Human Papillomavirus (HPV) Among Vaccinated Young Women During the First 8 Years After HPV Vaccine Introduction in a Community. Clin Infect Dis 63:1281-1287|
|Mesher, David; Soldan, Kate; Lehtinen, Matti et al. (2016) Population-Level Effects of Human Papillomavirus Vaccination Programs on Infections with Nonvaccine Genotypes. Emerg Infect Dis 22:1732-40|
|Whittemore, Dana; Ding, Lili; Widdice, Lea E et al. (2016) Distribution of Vaccine-Type Human Papillomavirus Does Not Differ by Race or Ethnicity Among Unvaccinated Young Women. J Womens Health (Larchmt) 25:1153-1158|
|Drolet, Mélanie; Bénard, Élodie; Boily, Marie-Claude et al. (2015) Population-level impact and herd effects following human papillomavirus vaccination programmes: a systematic review and meta-analysis. Lancet Infect Dis 15:565-80|