Estimated Number of Cases of High-Grade Cervical Lesions Diagnosed Among Women - United States, 2008 and 2016.

Human papillomavirus (HPV) causes approximately 30,000 cancers in the United States annually (1). HPV vaccination was introduced in 2006 to prevent HPV-associated cancers and diseases (1). Cervical cancer is the most common HPV-associated cancer in women (1). Whereas HPV-associated cancers typically take decades to develop, screen-detected high-grade cervical lesions (cervical intraepithelial neoplasia grades 2 [CIN2], 3 [CIN3], and adenocarcinoma in situ, collectively CIN2+) develop within a few years after infection and have been used to monitor HPV vaccine impact (1-3). CDC analyzed data from the Human Papillomavirus Vaccine Impact Monitoring Project (HPV-IMPACT), a population-based CIN2+ surveillance system, to describe rates of CIN2+ among women aged ≥18 years during 2008-2016. Age-specific rates were applied to U.S. population data to estimate the total number of CIN2+ cases diagnosed in the United States in 2008* and in 2016. From 2008 to 2016, the rate of CIN2+ per 100,000 women declined significantly in women aged 18-19 years and 20-24 years and increased significantly in women aged 40-64 years. In the United States in 2008, an estimated 216,000 (95% confidence interval [CI] = 194,000-241,000) CIN2+ cases were diagnosed, 55% of which were in women aged 18-29 years; in 2016, an estimated 196,000 (95% CI = 176,000-221,000) CIN2+ cases were diagnosed, 36% of which were in women aged 18-29 years. During 2008 and 2016, an estimated 76% of CIN2+ cases were attributable to HPV types targeted by the vaccine currently used in the United States. These estimates of CIN2+ cases likely reflect changes in CIN2+ detection resulting from updated cervical cancer screening and management recommendations, as well as primary prevention through HPV vaccination. Increasing coverage of HPV vaccination in females at the routine age of 11 or 12 years and catch-up vaccination through age 26 years will contribute to further reduction in cervical precancers.

Declines in Vaccine-Type Human Papillomavirus Prevalence in Females Across Racial/Ethnic Groups: Data From a National Survey.

PURPOSE: To monitor human papillomavirus (HPV) vaccine impact in the U.S., we evaluated quadrivalent vaccine (4vHPV)-type prevalence among females aged 14-34 years in the prevaccine (2003-2006) and vaccine (2013-2016) eras overall and by race/ethnicity in the National Health and Nutrition Examination Survey. METHODS: We analyzed HPV DNA prevalence in self-collected cervicovaginal specimens, demographic characteristics, sexual behavior, and self-reported/parent-reported vaccination status. We compared prevaccine to vaccine era 4vHPV-type prevalence, using unadjusted and adjusted prevalence ratios (PR and aPR) and 95% confidence intervals (CIs). PRs were calculated by race/ethnicity (non-Hispanic white [NHW], non-Hispanic black [NHB], and Mexican American [MA]). Overall aPRs were adjusted for race/ethnicity, lifetime sex partners, and poverty. RESULTS: Overall, 4,674 females had HPV typing results; 3,915 reported NHW, NHB, or MA race/ethnicity. Vaccination coverage of ≥1 dose was 53.9% among 14- to 19-year-olds (NHW 52.6%, NHB 58.1%, and MA 59.5%) and 51.5% among 20- to 24-year-olds (NHW 58.8%, NHB 45.0%, MA 33.8%). Among 14- to 19-year-olds, 4vHPV-type prevalence decreased overall (11.5% to 1.8%; aPR = .14 [CI: .08-.24]) and in NHW (PR = .14 [CI: .06-.29]), NHB (PR = .26 [CI: .12-.54]), and MA (PR = .13 [CI: .03-.53]). In 20- to 24-year-olds, 4vHPV-type prevalence decreased overall (18.5% to 5.3%; aPR = .29 [CI: .15-.56]) and in NHW (PR = .27 [CI: .11-.67]) and NHB (PR = .38 [CI: .18-.80]). No significant declines were observed in older age groups. CONCLUSIONS: Within 10 years of vaccine introduction, 4vHPV-type prevalence declined 86% among 14- to 19-year-olds, with declines observed in NHW, NHB, and MA females, and 71% among 20- to 24-year-olds, with declines in NHW and NHB females. These extraordinary declines should lead to substantial reductions in HPV-associated cancers.

Trends in Human Papillomavirus Vaccine Types 16 and 18 in Cervical Precancers, 2008-2014.

BACKGROUND: The impact of human papillomavirus (HPV) vaccination has been observed in the United States through declining cervical precancer incidence in young women. To further evaluate vaccine impact, we described trends in HPV vaccine types 16/18 in cervical precancers, 2008-2014. METHODS: We analyzed data from a 5-site, population-based surveillance system. Archived specimens from women age 18-39 years diagnosed with cervical intraepithelial neoplasia grades 2-3 or adenocarcinoma in situ (CIN2+) were tested for 37 HPV types. We described the proportion and estimated number of cases of CIN2+ by HPV-type groups over time. Trends in HPV16/18-positive CIN2+ were examined, overall and by vaccination status, age, histologic grade, and race/ethnicity, using Cochrane-Armitage tests. RESULTS: In 10,206 cases, the proportion and estimated number of cases of HPV16/18-positive CIN2+ declined from 52.7% (1,235 cases) in 2008 to 44.1% (819 cases) in 2014 (P < 0.001). Declining trends in the proportion of HPV16/18-positive CIN2+ were observed among vaccinated (55.2%-33.3%, P < 0.001) and unvaccinated (51.0%-47.3%, P = 0.03) women; ages 18-20 (48.7%-18.8%, P = 0.02), 21-24 (53.8%-44.0%, P < 0.001), 25-29 (56.9%-42.4%, P < 0.001), and 30-34 (49.8%-45.8%, P = 0.04) years; CIN2 (40.8%-29.9%, P < 0.001) and CIN2/3 (61.8%-46.2%, P < 0.001); non-Hispanic white (59.5%-47.9%, P < 0.001) and non-Hispanic black (40.7%-26.5%, P < 0.001). CONCLUSIONS: From 2008-2014, the proportion of HPV16/18-positive CIN2+ declined, with the greatest declines in vaccinated women; declines in unvaccinated women suggest herd protection. IMPACT: The declining proportion of HPV16/18-positive CIN2+ provides additional evidence of vaccine impact in the United States.