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Background:  Human papillomavirus (HPV) vaccine effectiveness and herd protection are not well established in community settings. Our objective was to determine trends in vaccine-type HPV in young women during the 8 years after vaccine introduction, to assess changes in HPV prevalence and characterize herd protection in a community., Methods:  We recruited 3 samples of sexually experienced, 13-26-year-old adolescent girls and young women (hereafter women; N = 1180) from 2006-2014: before widespread vaccine introduction (wave 1) and 3 (wave 2) and 7 (wave 3) years after vaccine introduction. We determined the prevalence of vaccine-type HPV (HPV-6, -11, -16, and -18) among all, vaccinated, and unvaccinated women at waves 1, 2, and 3, adjusted for differences in participant characteristics, then examined whether changes in HPV prevalence were significant using inverse propensity score-weighted logistic regression., Results:  Vaccination rates increased from 0% to 71.3% across the 3 waves. Adjusted vaccine-type HPV prevalence changed from 34.8% to 8.7% (75.0% decline) in all women, from 34.9% to 3.2% (90.8% decline) in vaccinated women, and from 32.5% to 22.0% (32.3% decline) in unvaccinated women. Among vaccinated participants, vaccine-type HPV prevalence decreased significantly from wave 1 to wave 2 (adjusted odds ratio, 0.21; 95% confidence interval, .13-.34) and from wave 1 to wave 3 (0.06; .03-.13). The same decreases were also significant among unvaccinated participants (adjusted odds ratios, 0.44; [95% confidence interval, .27-.71] and 0.59; [.35-.98], respectively)., Conclusions:  The prevalence of vaccine-type HPV decreased >90% in vaccinated women, demonstrating high effectiveness in a community setting, and >30% in unvaccinated women, providing evidence of herd protection., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.)

PurposeThe aims of this study were to determine prevalence of and factors associated with any human papillomavirus (HPV) and vaccine-type HPV among young men after vaccine introduction, stratified by vaccination status.MethodsYoung men were recruited from clinical sites from 2013 to 2015, completed a survey, and were tested for 36 anogenital HPV types. We determined factors associated with ≥1 HPV type among all participants, and vaccine-type HPV (HPV6, 11, 16, and/or 18) among all, vaccinated and unvaccinated participants, using multivariable regression.ResultsMean age was 21.5 years and 26% had received at least one HPV vaccine dose. HPV prevalence was lower in vaccinated versus unvaccinated young men (50.5% vs. 62.6%, p = .03). HPV positivity was discordant by anogenital site. At both sites, 59.4% were positive for ≥1 HPV type and 26.0% for ≥1 4-valent vaccine type. In multivariable logistic regression, factors associated with ≥1 HPV type among all participants were frequency of oral sex (odds ratio [OR] = 1.80, 95% confidence interval [CI] = 1.00-3.24), recent smoking (OR = 1.84, CI = 1.17-2.90), and sexually transmitted infection history (OR = 1.56, CI = 1.02-2.38). Factors associated with vaccine-type HPV among all participants were white versus black race (OR = 1.91, CI = 1.10-3.34) and gonorrhea history (OR = 2.52, CI = 1.45-4.38); among vaccinated participants were private versus Medicaid insurance (OR = 5.6, CI = 1.46-20.4) and private versus no insurance (OR = 15.9, CI = 3.06-83.3); and among unvaccinated participants was gonorrhea history (OR = 1.83, CI = 1.03-3.24).ConclusionsAnogenital HPV prevalence was high and vaccination rates low among young men 2-4 years after vaccine introduction, underscoring the urgency of increasing vaccination rates and vaccinating according to national guidelines.

Background Delayed completion of human papillomavirus vaccination (4vHPV) series is common. We sought to identify factors associated with delay. Methods This substudy was part of a large prospective, multi-site study recruiting 9–17 year old girls at the time of their third 4vHPV dose to assess immunogenicity associated with prolonged dosing intervals. At participating sites, parents/legal guardians (caregivers) of all enrolled girls (9–17 years old) and enrolled girls aged 14–17 years were approached for participation. Caregivers completed a questionnaire measuring adolescent and caregiver sociodemographic characteristics, caregiver attitudes and beliefs about on-schedule HPV vaccination and HPV vaccine safety, adolescent’s health behaviors, barriers to accessing health care, provider office vaccination practices and a Rapid Estimate of Adult Literacy in Medicine (REALM). Participating girls completed a separate questionnaire measuring their attitudes and beliefs about on-schedule HPV vaccination and HPV vaccine safety. Delay was defined as receiving the third 4vHPV dose >12 months after the first. Bivariate, multinomial logistic regression and multivariate logistic regression analyses were used to identify factors predicting delayed completion. Results Questionnaires were completed by 482 caregivers and 386 adolescents; 422 caregivers completed a REALM. Delayed 4vHPV dosing occurred in most adolescents (67%). In multivariate analyses, predictors of delayed completion included caregiver demographic factors (self-reported black vs. white race and high school or less education vs. college or more) and an interaction between caregiver’s inability to get an immunization appointment as soon as needed and adolescent’s type of insurance. Conclusions Caregiver’s race and educational level, accessibility of immunization appointments, and adolescent’s insurance type were found to be related to delays in completion of 4vHPV, but caregiver or adolescent attitudes and beliefs about on-schedule HPV vaccination or HPV vaccine safety were not. Therefore, interventions to improve adherence to recommended vaccination schedules could benefit from a focus on improving access to immunizations. ClinicalTrials.gov (NCT01030562). [ABSTRACT FROM AUTHOR]

Background The originally recommended dosing schedule, 0, 2, 6 months, for the 3-dose quadrivalent human papillomavirus vaccine (4vHPV) was often not followed, resulting in longer than recommended intervals between doses and interest in the effect of prolonged intervals. Recent two-dose recommendations require investigations into the effect of delaying dose 2. Methods This multi-site, prospective study enrolled healthy 9–17 year old girls (n = 1321) on the day of or within 28 days following a third dose of 4vHPV vaccination. Antibody titers to 4vHPV types were measured at one and six months post-dose 3 from all participants and post-dose 2 from participants who were on time for dose 3. To compare antibody responses, participants were categorized into groups: second and third doses on time (control group); on-time dose 2, substantially late dose 3 (group 2); substantially late dose 2, on-time dose 3 (group 3); both doses substantially late (group 4). Analyses compared age-adjusted geometric mean titers (GMTs) at one-month and six-months post-dose 3, effect of delaying the second dose, and two versus three doses as well as post-dose 2 GMTs, stratified by age. Results Compared to on-time dosing, one-month post-dose 3 GMTs were non-inferior in groups 2, 3, and 4 and were superior in group 2. Six month post-dose 3 GMTs were superior in groups 2, 3, and 4 for each genotype, except HPV 18 in group 3. Age-adjusted post does 2 titers were significantly lower than post-dose 3 titers when dose 2 was on time but were significantly higher when dose 2 was substantially late. Participants ≥15 years old had no difference in post-dose 2 titers compared to <15 year olds when dose 2 was substantially delayed. Conclusions Prolonged intervals between doses do not appear to diminish and may enhance antibody response to 4vHPV. ClinicalTrials.gov ( NCT00524745 ). [ABSTRACT FROM AUTHOR]

Background: Previous studies have demonstrated racial and ethnic differences in the distribution of human papillomavirus (HPV) types among adult women with cervical precancers. The aim of this study was to determine whether the distribution of vaccine-targeted HPV types varies by race/ethnicity among unvaccinated young women. Materials and Methods: A secondary analysis was performed using data from four studies of sexually experienced, unvaccinated, 13-26-year-old women. Participants completed surveys and provided a cervicovaginal swab for HPV DNA testing. Multivariable logistic regression analyses were performed to examine whether race, ethnicity, and other factors were associated with type-specific HPV infection among the overall sample and among HPV-infected participants. Models controlled for age, HPV knowledge, sexual behaviors, substance use, and random study effect. Results: The mean age of participants ( N = 841) was 19.3 years; 64.4% were black and 8.9% Hispanic. Black women were more likely than white women to be positive for ≥1 HPV type (odds ratio [OR] 1.83, 95% CI 1.30-2.58) and Hispanic women were less likely than non-Hispanic women to be positive for ≥1 HPV type (OR 0.47, 95% CI 0.24-0.92). However, among all young women and HPV-infected women, neither race nor ethnicity was associated with positivity for HPV types targeted by the following vaccines: 2-valent (HPV16 and/or 18), 4-valent (HPV6, 11, 16, and/or 18), or 9-valent (HPV6, 11, 16, 18, 31, 33, 45, 52, and/or 58). Conclusion: The prevalence of HPV types targeted by the 2-valent, 4-valent, and 9-valent vaccines did not differ by race or ethnicity among all and among HPV-infected women in this sample. [ABSTRACT FROM AUTHOR]

Purpose. We examined patient- and provider-level factors associated with initiation of three adolescent immunizations among 13 to 18 year olds in an adolescent primary care clinic. Methods. Data were extracted retrospectively from medical records. Logistic regression models identified associations with immunization initiation. Post hoc analyses stratified by gender were conducted to examine provider-type contribution to human papillomavirus (HPV) immunization initiation. Results. Among 2932 adolescents, rates of meningococcal and varicella immunization initiation differed by age. Girls were more likely to have initiated HPV immunization than boys. The probability of girls initiating HPV immunization was the same when last seen by advanced practice nurses (APNs) versus physicians, but the probability of boys initiating HPV immunization was lower when last seen by APNs. Conclusions. Differences in HPV immunization initiation were observed between genders, and for boys, between APN versus physician at last clinic visit. This may reflect changes to HPV immunization recommendations for boys and APNs having shorter clinic visits. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objectives of this study were to determine (1) adherence to the immunization schedule for the human papillomavirus quadrivalent vaccine and (2) factors associated with completion of the 3-dose series. METHODS: This was a retrospective review of health information records from an academic medical center. The sample included all 9- to 26-year-old female patients who initiated vaccination within 2 years after quadrivalent vaccine availability. Multivariable logistic regression models were estimated to determine associations with completion of the 3-dose series within 7 and 12 months. RESULTS: Among the 3297 female patients who initiated vaccination with human papillomavirus quadrivalent vaccine, 67% self-identified as black and 29% self-identified as white. Fewer than 3% of vaccine doses were received earlier than recommended, but >50% of doses were received late. Completion rates were 14% by 7 months and 28% by 12 months. Independent predictors of completion by 7 months included white versus black race (odds ratio [OR]: 2.04 [95% confidence interval (Cl): 1.64-2.561; P < .001), use of contraception that required intramuscular injections every 3 months (OR: 1.53 [95% Cl: 1.12-1.951; P < .001), and private versus public insurance (OR: 1.31 [95%Cl: 1.06-1.631; P < .05). Age and clinic type were not independent predictors of completion. CONCLUSIONS: Adherence to recommended intervals and completion of the vaccine series were low. Lower rates of completion in black patients compared with white patients raises concern that disparities in vaccine completion could exacerbate existing disparities in cervical cancer. [ABSTRACT FROM AUTHOR]