Reduction in HPV 16/18-associated high grade cervical lesions following HPV vaccine introduction in the United States – 2008–2012

BackgroundPrevention of pre-invasive cervical lesions is an important benefit of HPV vaccines, but demonstrating impact on these lesions is impeded by changes in cervical cancer screening. Monitoring vaccine-types associated with lesions can help distinguish vaccine impact from screening effects. We examined trends in prevalence of HPV 16/18 types detected in cervical intraepithelial neoplasia 2, 3, and adenocarcinoma in situ (CIN2+) among women diagnosed with CIN2+ from 2008 to 2012 by vaccination status. We estimated vaccine effectiveness against HPV 16/18-attributable CIN2+ among women who received ≥1 dose by increasing time intervals between date of first vaccination and the screening test that led to detection of CIN2+ lesion.MethodsData are from a population-based sentinel surveillance system to monitor HPV vaccine impact on type-specific CIN2+ among adult female residents of five catchment areas in California, Connecticut, New York, Oregon, and Tennessee. Vaccination and cervical cancer screening information was retrieved. Archived diagnostic specimens were obtained from reporting laboratories for HPV DNA typing.ResultsFrom 2008 to 2012, prevalence of HPV 16/18 in CIN2+ lesions statistically significantly decreased from 53.6% to 28.4% among women who received at least one dose (P_trend < .001) but not among unvaccinated women (57.1% vs 52.5%; P_trend = .08) or women with unknown vaccination status (55.0% vs 50.5%; P_trend = .71). Estimated vaccine effectiveness for prevention of HPV 16/18-attributable CIN2+ was 21% (95% CI: 1–37), 49% (95% CI: 28–64), and 72% (95% CI: 45–86) in women who initiated vaccination 25–36 months, 37–48 months, and >48 months prior to the screening test that led to CIN2+ diagnosis.ConclusionsPopulation-based data from the United States indicate significant reductions in CIN2+ lesions attributable to types targeted by the vaccines and increasing HPV vaccine effectiveness with increasing interval between first vaccination and earliest detection of cervical disease.     

Provider communication and HPV vaccination: The impact of recommendation quality

BackgroundReceiving a healthcare provider's recommendation is a strong predictor of HPV vaccination, but little is known empirically about which types of recommendation are most influential. Thus, we sought to investigate the relationship between recommendation quality and HPV vaccination among U.S. adolescents.MethodsIn 2014, we conducted a national, online survey of 1495 parents of 11–17-year-old adolescents. Parents reported whether providers endorsed HPV vaccination strongly, encouraged same-day vaccination, and discussed cancer prevention. Using an index of these quality indicators, we categorized parents as having received no, low-quality, or high-quality recommendations for HPV vaccination. Separate multivariable logistic regression models assessed associations between recommendation quality and HPV vaccine initiation (≥1 dose), follow through (3 doses, among initiators), refusal, and delay.ResultsAlmost half (48%) of parents reported no provider recommendation for HPV vaccination, while 16% received low-quality recommendations and 36% received high-quality recommendations. Compared to no recommendation, high-quality recommendations were associated with over nine times the odds of HPV vaccine initiation (23% vs. 74%, OR = 9.31, 95% CI, 7.10–12.22) and over three times the odds of follow through (17% vs. 44%, OR = 3.82, 95% CI, 2.39–6.11). Low-quality recommendations were more modestly associated with initiation (OR = 4.13, 95% CI, 2.99–5.70), but not follow through. Parents who received high- versus low-quality recommendations less often reported HPV vaccine refusal or delay.ConclusionsHigh-quality recommendations were strongly associated with HPV vaccination behavior, but only about one-third of parents received them. Interventions are needed to improve not only whether, but how providers recommend HPV vaccination for adolescents.     

No increased risk of Guillain-Barré syndrome after human papilloma virus vaccine: A self-controlled case-series study in England

ObjectiveTo investigate the risk of Guillain-Barré syndrome (GBS) after human papilloma virus (HPV) vaccine given to 12–18 year old girls in England.MethodsHospital Episode Statistics (HES) were searched using data to March 2016 to identify incident cases of GBS in female patients aged from 11 to 20 years eligible to have received the HPV vaccine since its introduction as a 3 dose schedule in September 2008. Diagnosis was confirmed by the case’s general practitioner (GP) who also provided HPV vaccination dates. The risk of admission within 3 months (primary risk window) 6 and 12 months of any dose was assessed using the self-controlled case-series (SCCS) method in vaccinated girls with age, season and time-period adjustment. The risk before and after the change in 2012 from bivalent vaccine to quadrivalent vaccine was also assessed.ResultsA total 244 episodes were initially identified which reduced to 101 episodes in 100 girls when just including cases where the GP could be contacted, at least one vaccine dose was given, and GBS was confirmed or classed as probable. Nine, 14 and 24 GBS admissions occurred within 3, 6, 12 months of a dose respectively. The relative incidence (RI) for the 3 month risk period was 1.04 (95% confidence interval 0.47–2.28), for the 6 month period 0.83 (0.41–1.69) and for the 12 month period 1.10 (0.57–2.14). When restricting to 79 confirmed cases the RI in the 3 month risk period was 1.26 (0.55–2.92) and the RI 1.61 (0.39–6.54) for quadrivalent vaccine compared to 0.84 (0.30–2.34) for bivalent.ConclusionWe found no evidence of an increased risk of GBS following HPV vaccination in England and, based on the upper end of the 95% CI for the RI and the number of HPV vaccine doses given in England, can exclude a risk of about 1 per million doses.     

Safety and immunogenicity of a 9-valent HPV vaccine in females 12–26 years of age who previously received the quadrivalent HPV vaccine

ObjectivesTo assess the safety and immunogenicity of the investigational 9-valent (6/11/16/18/31/33/45/52/58) HPV (9vHPV) vaccine in prior recipients of a 3-dose regimen of quadrivalent (6/11/16/18) HPV (qHPV) vaccine.MethodsV503-006 was a randomized, double-blinded, safety/tolerability and immunogenicity study of the 9vHPV vaccine in females 12–26 years of age who were previously vaccinated with qHPV vaccine. Subjects were randomized in a 2:1 ratio to receive 3 doses of 9vHPV vaccine (n = 618) or saline placebo (n = 306) at day 1, month 2, and month 6. Systemic, injection-site and serious adverse experiences (AEs) were monitored. Serum samples were collected at day 1, month 2, and month 7. Anti-HPV 6/11/16/18/31/33/45/52/58 titers were measured using the 9-valent HPV competitive Luminex Immunoassay (cLIA).ResultsThe frequency of injection-site AEs (days 1–5 following any vaccination) was higher in the 9vHPV vaccine group than in the placebo group (91.1% and 43.9%, respectively). The frequencies of vaccine-related systemic AEs (days 1–15 following any vaccination) were generally comparable between the 2 groups (30.6% in the 9vHPV vaccine group, and 25.9% in the placebo group). One vaccine-related serious AE was reported in each of the 9vHPV vaccine and placebo groups. Few subjects (9vHPV = 0.5%; placebo = 0%) discontinued due to an AE. At 4 weeks post-dose 3, over 98% of subjects in the 9vHPV vaccine group were seropositive for HPV types 31/33/45/52/58, with marked elevations in cLIA geometric mean titers (GMTs) to these HPV types. Anti-HPV 31/33/45/52/58 GMTs were lower than in subjects administered 9vHPV vaccine who had not previously received qHPV vaccine (based on cross-study analyses); the clinical significance of this difference is unknown.ConclusionsAdministration of a 3-dose regimen of 9vHPV vaccine to adolescent girls and young women 12–26 years of age who are prior qHPV vaccine recipients is highly immunogenic with respect to HPV types 31/33/45/52/58 and generally well tolerated.     

Correlates of HPV vaccine uptake in school-based routine vaccination of preadolescent girls in Norway: A register-based study of 90,000 girls and their parents

ObjectiveTo assess demographic, socioeconomic and behavioural correlates of HPV vaccination of preadolescent girls in a publicly funded, school-based vaccination programme.MethodsData for all Norwegian girls born 1997–1999, eligible for routine school-based HPV vaccination in 2009–2011 (n = 90,842), and their registered mother and father, were merged from national registries. Correlates of girl vaccination status were analysed by unadjusted and multivariable logistic regression.ResultsIn total, 78.2% of the girls received the first dose of the HPV vaccine, 74.6% received three doses, and 94.8% received the MMR vaccine. Correlates associated with initiation of HPV vaccination included parental age, income and education, maternal occupational status and cervical screening attendance, and girl receipt of the MMR vaccine. Rates of completion of HPV vaccination among initiators were high, and disparities in completion were negligible. Maternal and paternal correlates of daughter HPV vaccination status were similar.ConclusionsRoutine school-based vaccination generally provides equitable delivery, yet some disparities exist. Information campaigns designed to reach the sub-groups with relatively low vaccine uptake could reduce disparities. In none of the sub-groups investigated did uptake of the HPV vaccine approach that of the MMR vaccine, further demonstrating a general potential for improvement in HPV vaccine uptake.     

Association of both consistency and strength of self-reported clinician recommendation for HPV vaccination and HPV vaccine uptake among 11- to 12-year-old children

PurposeWe tested the hypotheses that consistency and strength of clinician recommendation of the human papillomavirus (HPV) vaccination would be associated with vaccine delivery rates.MethodsFrom October 2015 through January 2016, we conducted a survey of primary care clinicians (n = 227) in Southeastern Minnesota to evaluate clinician behaviors regarding HPV vaccination. The survey response rate was 41.0% (51 clinical sites). We used the Rochester Epidemiology Project, a clinical data linkage infrastructure, to ascertain clinical site-level HPV vaccination rates. We examined associations of clinician self-reports of both the consistency and strength of their recommendations for HPV vaccination for patients aged 11–12 years (n = 14,406) with site-level vaccination rates.ResultsThe majority of clinicians reported consistently (always or usually) recommending the HPV vaccine to females (79.0%) and to males (62.2%); 71.9% of clinicians reported strongly recommending the vaccine to females while 58.6% reported strongly recommending to males. Consistency and strength of recommending the HPV vaccine was significantly higher among those practicing in pediatrics and board certified in pediatrics compared to family medicine. Higher rates of initiation (1 dose) [Incidence Rate Ratio (IRR) = 1.05; 95% CI (1.01–1.09)] and completion (3 doses) [IRR = 1.08; 95% CI (1.02–1.13)] were observed among clinical sites where, on average, clinicians more frequently reported always or usually recommending the vaccine for females compared to sites where, on average, clinicians reported recommending the vaccine less frequently. Similarly, higher rates of initiation [IRR = 1.03; 95% CI (1.00–1.06)] and completion [IRR = 1.04; CI (1.00, 1.08)] were observed among sites where clinicians reported strongly recommending the vaccine to females more frequently compared to sites where, on average, clinicians reported strongly recommending the HPV vaccine less frequently; similar associations were observed for male initiation [IRR = 1.05; CI (1.02,1.08)] and completion [IRR = 1.05; 95% CI (1.01, 1.09)].ConclusionsConsistency and strength of HPV vaccination recommendation was associated with higher vaccination rates.     

General practitioners’ attitudes and behaviors toward HPV vaccination: A French national survey

ObjectiveGeneral practitioners (GPs) play a crucial role in human papillomavirus (HPV) vaccine acceptance in France. We sought to study: (1) GPs’ perceptions of its risks and efficacy and their recommendation behavior; (2) the relative importance of factors associated with the frequency of their recommendations.MethodsCross-sectional observational study in 2014 nested in a national panel of 1712 randomly selected GPs in private practice in France (response rate: 92.4%). We used model averaging to analyze the associations of self-reported frequency of GPs’ HPV vaccine recommendations with their perception of its risk-benefit balance and their opinions about the utility of vaccines in general.ResultsOverall, 72% of participants reported frequently recommending HPV vaccination; 60% considered that not enough is known about its risks. The model averaging showed that the factors most associated with infrequent recommendation of this vaccine by GPs were: unfavorable perceptions of its risk-benefit balance (OR = 0.13; 95%CI = 0.09–0.21; partial R² = 0.10), a decision not to vaccinate one's own daughter(s) with this vaccine (OR = 0.13; 95%CI = 0.07–0.24; partial R² = 0.05), and doubts about vaccine utility in general (OR = 0.78; 95%CI = 0.71–0.86; partial R² = 0.03).ConclusionAlthough nearly three-quarters of French GPs frequently recommended the HPV vaccine, our findings indicate that a substantial percentage of them are hesitant about it. Doubts about its risks and efficacy strongly influence their recommendation behavior. More research is warranted to help design and evaluate tailored tools and multicomponent intervention strategies to address physician's hesitancy about this vaccine.     

HPV vaccine for teen boys: Dyadic analysis of parents' and sons' beliefs and willingness

ObjectiveParents and adolescents often decide together whether the child should receive human papillomavirus (HPV) vaccine. However, few studies have investigated the dyadic nature of beliefs that affect this process.MethodData came from the 2010 HPV Immunization in Sons (HIS) Study, a national sample of 412 parents and their adolescent sons. We conducted dyadic multivariate logistic regression to examine the relationships between parents' and sons' HPV vaccine beliefs and their willingness to have the son receive the vaccine.ResultsLess than half of parents and sons were willing to have the sons receive HPV vaccine (43% and 29%, respectively). Willing parents and sons anticipated greater regret if the son did not receive HPV vaccine but later contracted an HPV infection (parent odds ratio [OR] = 1.72, 95% confidence interval [CI] = 1.24–2.40; son OR = 1.51, 95% CI = 1.04–2.19) (both p < .05). Lower concerns about side effects, such as pain and fainting, were also associated with willingness.ConclusionParents and sons were more willing to have the son receive HPV vaccine if they had higher anticipated regret about potential HPV infection and lower concerns about side effects. Communication campaigns may be able to target these beliefs to increase parents' and sons' willingness to seek HPV vaccination.     

Correlates of receiving recommended adolescent vaccines among youth with special health care needs: Findings from a statewide survey

BackgroundMany youth with special health care needs (YSHCN) have not received recommended adolescent vaccines, yet data are lacking on correlates of vaccination among this population. Such information can identify subgroups of YSHCN that may be at risk for under-immunization and strategies for increasing vaccination.MethodsWe analyzed weighted data from a population-based sample of parents with an 11- to 17-year-old child with a special health care need from the 2010–2012 North Carolina Child Health Assessment and Monitoring Program (n = 604). We used ordinal logistic regression to identify correlates of how many recommended vaccines (tetanus booster, meningococcal, and HPV [at least one dose] vaccines) adolescents had received.ResultsOnly 12% of YSHCN (18% of females and 7% of males) had received all three vaccines. More YSHCN had received tetanus booster vaccine (91%) than meningococcal (28%) or HPV vaccines (32%). In multivariable analyses, YSHCN who were female (OR = 2.59, 95% CI: 1.57–4.24), ages 16–17 (OR = 2.06, 95% CI: 1.10–3.87), or who had a preventive check-up in the past year (OR = 2.98, 95% CI: 1.24–7.21) had received a greater number of the vaccines. YSHCN from households that contained a person with at least some college education had received fewer of the vaccines (OR = 0.57, 95% CI: 0.33–0.96). Vaccine coverage did not differ by type of special health care need.ConclusionsVaccine coverage among YSHCN is lacking and particularly low among those who are younger or male. Reducing missed opportunities for vaccination at medical visits and concomitant administration of adolescent vaccines may help increase vaccine coverage among YSHCN.     

Human papillomavirus vaccination receipt and provider counseling rates among high-risk patients

ObjectiveWe describe provider documented counseling patterns and perception regarding HPV vaccination among patients with a history of cervical dysplasia.MethodsAll patients ages 21–45 who underwent colposcopy at a single academic medical center from 2018 to 2020 were sent a self-administered survey through the electronic medical record patient portal to assess their attitudes regarding human papillomavirus (HPV) vaccination. Demographic information, HPV vaccination history, and documented obstetrics and gynecology provider counseling at the time of colposcopy were examined.ResultsOf 1465 patients, 434 (29.6 %) reported or had documented receipt of at least one dose of the human papillomavirus vaccine. The remainder reported they were not vaccinated or had no documentation of vaccination. Proportion of vaccinated patients was higher among White compared to Black and Asian patients (P = 0.02). On multivariate analysis, private insurance (aOR 2.2, 95 % CI 1.4–3.7) was associated with vaccinated status while Asian race (aOR 0.4, 95 % CI 0.2–0.7) and hypertension (aOR 0.2, 95 % CI 0.08–0.7) were less likely to be associated with vaccination status. Among patients with unvaccinated or unknown vaccination status, 112 (10.8 %) received documented counseling regarding catch-up human papillomavirus vaccination at a gynecologic visit. Patients seen by a sub-specialist obstetrics and gynecologic provider were more likely to have documented provider counseling regarding vaccination compared to those seen by a generalist obstetric/gynecologist provider (26 % vs 9.8 %, p < 0.001). Patients cited lack of physician discussion (53.7 %) and the belief that they were too old to receive the HPV vaccine (48.8 %) as the main reasons for remaining unvaccinated.ConclusionHPV vaccination and the rate of obstetric and gynecologic provider counseling regarding HPV vaccination among patients undergoing colposcopy remains low. When surveyed, many patients with a history of colposcopy cited provider recommendation as a factor in their decision to undergo adjuvant HPV vaccination, demonstrating the importance of provider counseling in this group.     

Age-specific effectiveness following each dose of acellular pertussis vaccine among infants and children in New Zealand

BackgroundThough it is believed the switch from whole cell to acellular pertussis vaccine has contributed to the resurgence of pertussis disease, few studies have evaluated vaccine effectiveness (VE) and duration of protection provided by an acellular vaccine schedule including three primary doses but no toddler-age dose. We assessed this schedule in New Zealand (NZ), a setting with historically high rates of pertussis disease, and low but recently improved immunisation coverage. We further evaluated protection following the preschool-age booster dose.MethodsWe performed a nested case-control study using national-level healthcare data. Hospitalised and non-hospitalised pertussis was detected among children 6 weeks to 7 years of age between January 2006 and December 2013. The NZ National Immunisation Register provided vaccination status for cases and controls. Conditional logistic regression was used to calculate dose-specific VE with duration of immunity examined by stratifying VE into ages aligned with the immunisation schedule.ResultsVE against pertussis hospitalisation was 93% (95% confidence interval [CI]: 87, 96) following three doses among infants aged 5–11 months who received three compared to zero doses. This protection was sustained through children’s fourth birthdays (VE ⩾ 91%). VE against non-hospitalised pertussis was also sustained after three doses, from 86% (95% CI: 80, 90) among 5–11 month olds to 84% (95% CI: 80, 88) among 3-year-olds. Following the first booster dose at 4 years of age, the protective VE of 93% (95% CI: 90, 95) among 4-year-olds continued through 7 years of age (VE ⩾ 91%).ConclusionsWe found a high level of protection with no reduction in VE following both the primary course and the first booster dose. These findings support a 3-dose primary course of acellular vaccine with no booster dose until 4 years of age.     

Effectiveness of HPV vaccines against genital warts in women from Valencia,Spain

ObjectivesTo assess the effectiveness of the HPV vaccines in preventing genital warts in young women.DesignPopulation-based study using health databases.SettingValencian Community (Spain).ParticipantsAll girls and women aged 14–19 years who were registered in the Valencian Community between January 2009 and December 2014 (n = 279,787).Main outcome measuresIncident cases of genital warts were defined as the first activation of diagnosis code ICD-9-CM 078.11 (Condyloma acuminatum) in primary care and outpatient clinics during the study period.ResultsThere were 612 cases of genital warts. The overall incidence rate was 75.8/100,000 person-years (95% CrI 69.7–81.8). There was a decrease in genital warts when female candidates to be vaccinated with quadrivalent HPV vaccine reached the age of 18 (in 2012), compared to previous years. Incidence of genital warts in unvaccinated women and those who received the bivalent vaccine was higher than in girls and women who received the quadrivalent HPV vaccine. The effectiveness of a three-dose regimen of the quadrivalent HPV vaccine was 77% (95 CrI: 66–85%), whereas that of a single dose was 61% (95 CrI: 20–87%). No effectiveness was seen with a full vaccination course with the bivalent HPV vaccine.ConclusionsThree doses of the quadrivalent HPV vaccine were effective against genital warts in our population. Moreover, with low vaccine coverage the incidence of genital warts decreased only in the vaccinated.     

Relationship status impacts primary reasons for interest in the HPV vaccine among young adult women

IntroductionThe HPV vaccine prevents HPV-related cancers and genital warts, which cause significant morbidity and mortality in the US. The vaccine is targeted toward 11–12 year old males and females, but is recommended for “catch-up” vaccination until age 26 for females. Young adult females (18–26 years) represent a unique group that may face distinct barriers to HPV vaccination, one of which is relationship status. The purpose of this study was to assess how relationship status impacts interest in HPV vaccination and primary reasons for non-vaccination among 18–26 year old young adult women.MethodsThe National Health Interview Survey 2010 was examined among unvaccinated females, 18–26 years (N = 1457). A survey-weighted logistic regression analysis with conversion to prevalence ratios assessed how interest in the HPV vaccine (yes/no) was influenced by relationship status (married, living with a partner, other, single) among young adult women. A Rao-Scott chi-square test examined differences between primary reasons for non-vaccination and relationship status among HPV vaccine uninterested women.ResultsAmong unvaccinated women, 31.4% were interested in the HPV vaccine. Women who were living with a partner (PR = 1.45, 95%CI 1.06–1.90) and single (PR = 1.42, 95%CI 1.11–1.76) were significantly more likely than married women to be interested in the HPV vaccine, while controlling for socio-demographic and other known risk factors. Additionally, primary reasons for non-vaccination differed based on relationship status among uninterested women (p < 0.01). Women who were married were more likely to cite not needing the vaccine compared to never married women (p < 0.05).ConclusionRelationship status in young adulthood impacts HPV vaccine interest and decision-making among a national sample of women. Primary reasons for non-interest in the vaccine may be shaped by attitudes and knowledge about the HPV vaccine that differ by relationship status. Future research is needed to elucidate ways to overcome relationship status as a barrier to HPV vaccination.     

Effect of number of human papillomavirus vaccine doses on guideline adherent cervical cytology screening among 19–26 year old females

PurposeLittle is known about how the number of HPV vaccine doses affect adherence to screening guidelines. This study compared adherence to cervical cancer screening by the number of HPV vaccine doses received by young women and assessed whether the specialty of vaccinating providers affected behavior.MethodsThis retrospective cohort study using administrative insurance claims records included 24,964 19–26 year old women who received at least 1 injection of the HPV vaccine between January 2006 and November 2009. Vaccinated young women continuously enrolled in a nationally-representative private insurance plan for 6 months prior to and 37 months after HPV vaccine administration were included. Logistic regression was used to compare the odds of Papanicolaou (Pap) testing 3 years after vaccine initiation by number of vaccine doses and provider type.ResultsIn this sample, 79.3% had a Pap test 3 years following vaccine initiation. Receiving 1 (aOR: 0.60, 95% CI 0.55–0.65) or 2 (aOR: 0.80, 95% CI 0.74–0.87) doses was associated with decreased odds of Pap testing compared to 3 doses. Many young women in our sample (16.5%) were diagnosed with cervical dysplasia prior to HPV vaccination. Patients vaccinated by non-obstetrician/gynecologists were less likely to get a Pap test following vaccination.ConclusionsWomen who received 1 or 2 doses of the HPV vaccine were less likely than those who received 3 doses to be screened for cervical cancer 3 years following vaccine initiation. Pediatricians and primary care physicians should convey the importance of initiating and continuing screening to HPV vaccinated patients.     

HPV vaccine acceptance among adolescent males and their parents in two suburban pediatric practices

PurposeTo measure HPV vaccine acceptance among unvaccinated adolescent males and parents and correlate acceptance with knowledge, awareness, and personal experience.MethodsAdolescent males ages 11–21 years old and their parents completed questionnaires measuring attitudes and knowledge about HPV vaccination and personal experience. Acceptance was defined as wanting the vaccine and conditional acceptance as wanting the vaccine if it would protect against genital warts or cervical cancer.ResultsAdolescent (n = 154) and parent (n = 121) vaccine acceptance was low (16% and 34%, respectively); however, conditional acceptance was higher. While adolescents had similar conditional acceptance for a vaccine against genital warts and cervical cancer, parents reported higher conditional acceptance for protection against genital warts. Independent predictors of acceptance included personal experience and demographic variables.ConclusionsHPV vaccine acceptance among adolescents and parents was low. Conditional acceptance levels highlight the importance of education about a few important benefits of HPV vaccination, which may increase vaccination rates.     

Validity of the estimates of oral cholera vaccine effectiveness derived from the test-negative design

BackgroundThe test-negative design (TND) has emerged as a simple method for evaluating vaccine effectiveness (VE). Its utility for evaluating oral cholera vaccine (OCV) effectiveness is unknown. We examined this method's validity in assessing OCV effectiveness by comparing the results of TND analyses with those of conventional cohort analyses.MethodsRandomized controlled trials of OCV were conducted in Matlab (Bangladesh) and Kolkata (India), and an observational cohort design was used in Zanzibar (Tanzania). For all three studies, VE using the TND was estimated from the odds ratio (OR) relating vaccination status to fecal test status (Vibrio cholerae O1 positive or negative) among diarrheal patients enrolled during surveillance (VE =  (1 − OR)×100%). In cohort analyses of these studies, we employed the Cox proportional hazard model for estimating VE (=1 − hazard ratio)×100%).ResultsOCV effectiveness estimates obtained using the TND (Matlab: 51%, 95% CI:37–62%; Kolkata: 67%, 95% CI:57–75%) were similar to the cohort analyses of these RCTs (Matlab: 52%, 95% CI:43–60% and Kolkata: 66%, 95% CI:55–74%). The TND VE estimate for the Zanzibar data was 94% (95% CI:84–98%) compared with 82% (95% CI:58–93%) in the cohort analysis. After adjusting for residual confounding in the cohort analysis of the Zanzibar study, using a bias indicator condition, we observed almost no difference in the two estimates.ConclusionOur findings suggest that the TND is a valid approach for evaluating OCV effectiveness in routine vaccination programs.     

HPV vaccination coverage of teen girls: The influence of health care providers

BackgroundBetween 2010 and 2014, the percentage of 13–17 year-old girls administered ≥3 doses of the human papilloma virus (HPV) vaccine (“fully vaccinated”) increased by 7.7 percentage points to 39.7%, and the percentage not administered any doses of the HPV vaccine (“not immunized”) decreased by 11.3 percentage points to 40.0%.ObjectiveTo evaluate the complex interactions between parents’ vaccine-related beliefs, demographic factors, and HPV immunization status.MethodsVaccine-related parental beliefs and sociodemographic data collected by the 2010 National Immunization Survey-Teen among teen girls (n = 8490) were analyzed. HPV vaccination status was determined from teens’ health care provider (HCP) records.ResultsAmong teen girls either unvaccinated or fully vaccinated against HPV, teen girls whose parent was positively influenced to vaccinate their teen daughter against HPV were 48.2 percentage points more likely to be fully vaccinated. Parents who reported being positively influenced to vaccinate against HPV were 28.9 percentage points more likely to report that their daughter's HCP talked about the HPV vaccine, 27.2 percentage points more likely to report that their daughter's HCP gave enough time to discuss the HPV shot, and 43.4 percentage points more likely to report that their daughter's HCP recommended the HPV vaccine (p < 0.05). Among teen girls administered 1–2 doses of the HPV vaccine, 87.0% had missed opportunities for HPV vaccine administration.ConclusionResults suggest that an important pathway to achieving higher ≥3 dose HPV vaccine coverage is by increasing HPV vaccination series initiation though HCP talking to parents about the HPV vaccine, giving parents time to discuss the vaccine, and by making a strong recommendation for the HPV. Also, HPV vaccination series completion rates may be increased by eliminating missed opportunities to vaccinate against HPV and scheduling additional follow-up visits to administer missing HPV vaccine doses.     

Effectiveness of a provider-focused intervention to improve HPV vaccination rates in boys and girls

BackgroundHPV vaccination is universally recommended for boys and girls, yet vaccination rates remain low nationwide.MethodsWe conducted a provider-focused intervention that included repeated contacts, education, individualized feedback, and strong quality improvement incentives to raise HPV vaccination rates at two federally qualified community health centers. To estimate the effectiveness of the intervention, rates of initiation of vaccination, and completion of the next needed HPV vaccination (dose 1, 2 or 3) among boys and girls ages 11–21 were compared at baseline and two follow-up periods in two intervention health centers (n  4093 patients) and six control health centers (n  9025 patients). We conducted multivariable logistic regression accounting for clustering by practice.ResultsGirls and boys in intervention practices significantly increased HPV vaccine initiation during the active intervention period relative to control practices (girls OR 1.6, boys OR 11; p < 0.001 for both). Boys at intervention practices were also more likely to continue to initiate vaccination during the post-intervention/maintenance period (OR 8.5; p < 0.01). Girls and boys at intervention practices were more also likely to complete their next needed HPV vaccination (dose 1, 2 or 3) than those at control practices (girls OR 1.4, boys OR 23; p < 0.05 for both). These improvements were sustained for both boys and girls in the post-intervention/maintenance period (girls OR 1.6, boys OR 25; p < 0.05 for both).ConclusionsProvider-focused interventions including repeated contacts, education, individualized feedback, and strong quality improvement incentives have the potential to produce sustained improvements in HPV vaccination rates.