Patient and clinician factors associated with uptake of the human papillomavirus (HPV) vaccine among adolescent patients of a primary care network

BackgroundHuman papillomavirus (HPV) vaccination rates for adolescents remain relatively low. The purpose of this study is to examine patient and clinician factors associated with HPV vaccination among patients, ages 11–17, of a large community-based primary care network.MethodsElectronic health records and administrative data from a large primary care network from January 2017 – June 2018 for patients ages 11–17 (n = 10,682) and the 198 primary care clinicians that saw them were analyzed. Mixed effects logistic regression models examined the association of patient and clinician factors with HPV vaccine uptake.ResultsMost patients (63.0%) had at least one dose of the HPV vaccine, and 37.7% were up to date. In adjusted analyses, patients who received the tetanus, diphtheria, and pertussis (Tdap) vaccine (OR = 2.8, 95% CI: 2.1–3.9) compared to those who did not receive the vaccine and patients with five or more medical visits (OR = 1.9, 95% CI: 1.6–2.2) had the greatest odds of being up to date with the HPV vaccine series. Compared to White patients, African American/Black (OR = 0.8, 95% CI: 0.6 – 1.0) and Alaskan Native/American Indian (OR = 0.5, 95% CI: 0.3–0.9) patients were less likely to be up to date. Boys were also less likely to be up to date with the HPV vaccine series compared to girls (OR = 0.7, 95% CI: 0.7–0.8). Additionally, patients with family/general practice primary care clinicians were less likely to have their patients up to date than those with pediatricians (OR = 0.8, 95% CI: 0.6 – 1.0).ConclusionHPV vaccine uptake varied by patient characteristics, heath care utilization and primary care clinician specialty. These findings may inform future evidence-based interventions aimed at increasing HPV vaccine uptake among adolescents by targeting patient sub-groups and reducing missed opportunities for vaccination.     

Safety and immunogenicity of a pichia pastoris-expressed bivalent human papillomavirus (types 16 and 18) L1 virus-like particle vaccine in healthy Chinese women aged 9–45 years: A randomized,double-blind,placebo-controlled phase 1 clinical trial

BackgroundWe evaluated the safety and immunogenicity of high and low doses of a novel pichia pastoris-expressed bivalent (types 16 and 18) human papillomavirus (HPV) virus-like particle vaccine.MethodsIn this randomized, double-blind, placebo-controlled phase 1 trial, we enrolled 160 healthy females aged 9–45 years in Guangxi, China who were randomized (1:1:2) to receive either low (0.5 mL) or high (1.0 mL) dosages of bivalent HPV vaccine, or placebo (aluminum adjuvant) in a 0, 2, 6 months schedule. Adverse events and other significant conditions that occurred within 30 days after each vaccination were recorded throughout the trial. Sera were collected at days 0, 60, 180 and 210 to measure anti-HPV 16/18 neutralizing antibodies.ResultsA total of 160 participants received at least one dose of the HPV vaccine and 152 completed the three dose vaccination series. Reporting rates of adverse events in placebo, low dose (0.5 mL) and high dose (1.0 mL) groups were 47.5 %, 55.0 % and 55.0 %, respectively. No serious adverse events occurred during this trial. 100 % of the participants who received three doses of the HPV vaccine produced neutralizing antibodies against HPV 16/18 vaccine. For HPV 16 and HPV 18, the geometric mean titers (GMTs) were similar between the low dose group (GMT_{HPV 16} = 10816 [95 % CI: 7824–14953]), GMT_{HPV 18} = 3966 [95 % CI: 2693–5841]) and high dose group (GMT _{HPV 16} = 14482 [95 % CI: 10848–19333], GMT _{HPV 18} = 3428 [95 % CI: 2533–4639]).ConclusionThe pichia pastoris-expressed bivalent HPV vaccine was safe and immunogenic in Chinese females aged 9–45 years. The low dosage (0.5 mL) was selected for further immunogenicity and efficacy study.     

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.     

Influenza vaccination uptake among Canadian adults before and during the COVID-19 pandemic: An analysis of the Canadian Longitudinal study on Aging (CLSA)

IntroductionUnderstanding how influenza vaccine uptake changed during the 2020/2021 influenza season compared to previous pre-pandemic seasons is a key priority, as is identifying the relationship between prior influenza vaccination and COVID-19 vaccine willingness.MethodsWe analyzed data from a large, nationally representative cohort of Canadian residents aged 50 and older to assess influenza vaccination status three times between 2015 and 2020. We investigated: 1) changes in self-reported influenza vaccine uptake, 2) predictors of influenza vaccine uptake in 2020/2021, and 3) the association between influenza vaccination history and self-reported COVID-19 vaccine willingness using logistic regression models.ResultsAmong 23,385 participants analyzed for aims 1–2, influenza vaccination increased over time: 14,114 (60.4%) in 2015–2018, 15,692 (67.1%) in 2019/2020, and 19,186 (82.0%; combining those already vaccinated and those planning to get a vaccine) in 2020/2021. After controlling for socio-demographics, history of influenza vaccination was most strongly associated with influenza vaccination in 2020/2021 (adjusted odds ratio [aOR] 147.9 [95% CI: 120.9–180.9]); this association remained after accounting for multiple health and pandemic-related factors (aOR 140.3 [95% CI: 114.5–171.8]). To a lesser degree, those more concerned about COVID-19 were also more likely to report influenza vaccination in fall 2020, whereas those reporting a very negative impact of the pandemic were less likely to get vaccinated. Among 23,819 participants with information on COVID-19 vaccine willingness during the last quarter of 2020 (aim 3), prior influenza vaccination was most strongly associated with willingness to get a COVID-19 vaccine (aOR 15.1 [95% CI: 13.5–16.8] for those who had received influenza vaccine at all previous timepoints versus none).ConclusionsOur analysis highlights the importance of previous vaccination in driving vaccination uptake and willingness. Efforts to increase vaccination coverage for influenza and COVID-19 should target individuals who do not routinely engage with immunization services regardless of demographic factors.     

Knowledge,attitudes, and practices regarding seasonal influenza vaccination during pregnancy in Costa Rica: A mixed-methods study

BackgroundInfluenza increases stillbirth risk, morbidity and mortality in pregnant women. Vaccination protects pregnant women against severe disease and indirectly protects their infants, but coverage among pregnant women remains low worldwide. We aimed to describe knowledge, attitudes, and practices (KAP) regarding seasonal influenza vaccination among postpartum women and prenatal care physicians in Costa Rica.MethodsWe conducted cross-sectional KAP surveys to women one to three days after childbirth at Costa Rican Social Security Fund maternity hospitals, and obstetricians and general practitioners who provided prenatal care in 2017. Principal components analysis, multiple imputation, and logistic regression were used to examine associations between influenza vaccination and demographics, prenatal care, and sources of information—separately for postpartum women and physicians. We also held two focus groups of six healthcare workers each to further describe vaccination KAP.ResultsWe surveyed 642 postpartum women and 146 physicians in maternity hospitals in five Costa Rican provinces of whom 85.5 % (95 % CI: 82.6 %-88.0 %) and 57.9 % (95 % CI: 49.6 %-65.7 %) were vaccinated for influenza, respectively. Factors associated with influenza vaccination for postpartum women included tetanus vaccination (aOR: 3.62, 95 % CI: 1.89–6.92); received vaccination recommendations from clinicians during prenatal check-ups (aOR: 3.39, 95 % CI: 2.06–5.59); had other children in household vaccinated for influenza (aOR: 2.25, 95 % CI: 1.08–4.68); and secondary/university education (aOR: 0.15–0.31) with no formal education as reference. For postpartum women, reasons for vaccination were perceived benefits for mother and infant, whereas not being offered vaccines was most cited for non-vaccination. Most prenatal care physicians recommended influenza vaccines during prenatal check-ups but believed vaccination causes flu-like symptoms.ConclusionVaccination campaigns and provisions of free vaccines effectively increased knowledge and coverage among women in Costa Rica. To improve access, women should be offered vaccines during prenatal care appointments. Educating healthcare workers about vaccine benefits for themselves and patients is needed to mitigate safety concerns.     

COVID-19 vaccine hesitancy among people living with HIV in a low-resource setting: A multi-center study of prevalence,correlates and reasons

BackgroundHesitancy to COVID-19 vaccine may worsen the burden of COVID-19 among people living with HIV (PLHIV), who are at a higher risk of COVID-19-related hospitalization and death, compared to HIV non-infected individuals. Therefore, we evaluate the predictors and reasons for COVID-19 vaccine hesitancy among unvaccinated PLHIV in six antiretroviral therapy (ART) clinics across northern Nigeria.MethodologyIn this cross-sectional study, conducted between October 2021 and February 2022 in six hospitals across two geopolitical regions of Nigeria, we utilized interviewer-administered questionnaires to assess COVID-19 vaccine hesitancy among a convenience sample of 790 eligible adult PLHIV. Hesitancy was defined as answering ‘no' or ‘maybe’ to a question asking participants their willingness to accept the COVID-19 vaccine. A multivariate logistic regression model was used to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of the factors associated with COVID-19 vaccine hesitancy among PLHIV.ResultsOf the total 660 unvaccinated participants included in the analysis (61.82% female, mean age [SD] of 39.76 [10.75]), 381 (57.72%) were hesitant to COVID-19 vaccine. Being 50 years and older (aOR: 0.43; 95% CI: 0.21–0.89), being unemployed (aOR: 0.57; 95% CI: 0.34–0.95), experiencing the adverse effects of ART (aOR: 0.36; 95% CI: 0.15–0.86), and perception of being at high risk of contracting COVID-19 (aOR: 0.22; 95% CI: 0.13–0.37) were associated with significantly lower odds of hesitancy. Conversely, being female (aOR: 1.64; 95% CI: 1.02–2.61) and attending ART clinics at state administrative capital cities (IIDH Kano [aOR: 2.40; 95% CI: 1.10–5.25], MMSH Kano [aOR: 5.59; 95% CI: 1.97–10.66], YSSH Damaturu [aOR: 9.88; 95% CI: 4.02–24.29] vs. GH Gashua) were associated with significantly higher odds of hesitancy. The most common reasons for hesitancy include fear of potential adverse effects, skepticism about vaccine efficacy, the rapid development of the COVID-19 vaccine, and the perceived lack of effort to develop a cure or vaccine for HIV/AIDS.ConclusionInterventions aimed at combating misperceptions and misinformation regarding the COVID-19 vaccination program may reduce the prevalence of COVID-19 vaccine hesitancy among unvaccinated PLHIV.     

Importance of human papillomavirus vaccination leaflets focusing on the safety profile targeted pediatricians in Japan

ObjectivesTo investigate the association between providing leaflets to support pediatricians in explaining the safety of the human papillomavirus (HPV) vaccine and mother’s decision to vaccinate their daughters in Japan.MethodsIn this cross-sectional study, we conducted a survey of mothers to evaluate the effect of leaflets that were created to support pediatricians in explaining the safety profile of the HPV vaccine. Mothers who provided consent for vaccination before receiving an explanation were excluded from the study. The primary outcome was the mother’s decision to vaccinate their daughters with the HPV vaccine after receiving an explanation from pediatricians using our leaflets.ResultsAmong 161 eligible mothers, 101 decided on HPV vaccination (decided group) and 60 did not (decided against group). There was no difference in the maternal background between the 2 groups. The decided group had a significantly more positive impression of the leaflets than the undecided group. In multivariable logistic regression analysis, a detailed explanation for possible adverse events and specific solutions to them was associated with the mother's decision to have their daughters vaccinated (odds ratio 2.35, 95% confidence interval 1.02–5.44), but not the pathology of cervical cancer and the HPV vaccination process.ConclusionLeaflets emphasizing an explanation of adverse events may contribute to mothers’ decision making for HPV vaccination.     

Identification of subgroups in the Danish population for targeted human papillomavirus vaccination efforts

BackgroundIn the Danish childhood vaccination program, the human papillomavirus (HPV) vaccination coverage is lower than for other vaccines. To tailor a targeted HPV vaccination effort, we aimed to identify girls in Denmark with lower first dose HPV vaccination coverage than girls in general.MethodsA population-based retrospective cohort study was performed of girls born in 2001–2004, residing in Denmark in September 2019 (N = 128,351). Data from the Danish Vaccination Register was linked to sociodemographic data from the Danish Civil Registration System and Statistics Denmark. Cox's proportional hazard regression models were used to compare vaccination uptake rates between subgroups of girls.ResultsHPV vaccination coverage at 14 years of age varied widely by municipality (53.4–80.6%). Girls living with neither of their parents had a lower chance of being vaccinated compared to girls living with both their parents (HR 0.43; 95% CI 0.41–0.46), likewise for girls attending special need education compared with girls attending public schools (HR 0.50; 95% CI 0.42–0.59). The vaccination uptake among immigrants was lower compared to Danish-born girls (HR 0.51; 95% CI 0.49–0.54), especially among immigrant girls whose parents had not passed any Danish exams. Finally, girls who were DTaP-IPV revaccinated had a 50% greater chance of being HPV vaccinated compared to girls who were not (HR 1.61; 95% CI 1.58–1.64).ConclusionTo increase the HPV vaccination uptake, we recommend vaccination efforts targeting girls living without any of their parents, girls attending special need education, immigrants, and girls who are not DTaP-IPV revaccinated. When targeting immigrants, the effort should focus on disseminating sufficient and understandable information about the Danish childhood vaccination program to the parents.     

Inactivated influenza vaccine and spontaneous abortion in the Vaccine Safety Datalink in 2012–13, 2013–14, and 2014–15

IntroductionA recent study reported an association between inactivated influenza vaccine (IIV) and spontaneous abortion (SAB), but only among women who had also been vaccinated in the previous influenza season. We sought to estimate the association between IIV administered in three recent influenza seasons and SAB among women who were and were not vaccinated in the previous influenza season.MethodsWe conducted a case-control study over three influenza seasons (2012–13, 2013–14, 2014–15) in the Vaccine Safety Datalink (VSD). Cases (women with SAB) and controls (women with live births) were matched on VSD site, date of last menstrual period, age group, and influenza vaccination status in the previous influenza season. Of 1908 presumptive cases identified from the electronic record, 1236 were included in the main analysis. Administration of IIV was documented in several risk windows, including 1–28, 29–56, and >56 days before the SAB date.ResultsAmong 627 matched pairs vaccinated in the previous season, no association was found between vaccination in the 1–28 day risk window and SAB (adjusted odds ratio (aOR) 0.9; 95% confidence interval (CI) 0.6–1.5). The season-specific aOR ranged from 0.5 to 1.7 with all CIs including the null value of 1.0. Similarly, no association was found among women who were not vaccinated in the previous season; the season-specific aOR in the 1–28 day risk window ranged from 0.6 to 0.7 and the 95% CI included 1.0 in each season. There was no association found between SAB and influenza vaccination in the other risk windows, or when vaccine receipt was analyzed relative to date of conception.ConclusionDuring these seasons we found no association between IIV and SAB, including among women vaccinated in the previous season. These findings lend support to current recommendations for influenza vaccination at any time during pregnancy, including the first trimester.     

Parental acceptance of typhoid conjugate vaccine for children aged 6 months to 15 years in an outbreak setting of Lyari Town Karachi,Pakistan

BackgroundThis study aimed to evaluate the parental acceptance of Typhoid Conjugate Vaccine (TCV) and to determine the predictors of TCV vaccination status among children in an outbreak setting of extensively drug resistant (XDR) typhoid fever in Karachi, Pakistan.MethodsA cross-sectional survey using the WHO recommended rapid vaccine coverage assessment technique was conducted. Out of 11, four union councils (UCs) in Lyari Town were randomly selected. A parent or primary caretaker from the eligible household was interviewed. Data were collected using a locally validated vaccine attitudes scale (VAS). Sum of scores was calculated for VAS. A higher score denoted negative attitudes and perceptions regarding TCV and vice versa. Multivariable logistic regression was performed to determine the predictors of TCV vaccination status.ResultsBased on the 14-item parental VAS, 78.0 % of the parents had a score between 0 to <40 and 22 % had a score ≥40. VAS score of <40 was significantly associated with higher odds of receiving TCV during the campaign setting (adjusted Odds Ratio (aOR): 1.30; 95 % Confidence Interval (CI): 1.02, 1.66). The odds of receiving TCV vaccination were higher among children whose parents were aware of the ongoing vaccination campaign in the area (aOR: 4.57; 95 % CI: 2.93, 7.12) and expressed willingness to get their child vaccinated against typhoid fever (aOR: 2.54; 95 % CI: 1.82, 3.55).ConclusionParental awareness of the ongoing vaccination campaign, positive perception and attitudes towards vaccine were found to be significantly associated with TCV vaccination among children. Appropriately structured pre-vaccination awareness campaigns focused on childhood vaccination targeted towards parents are necessary to improve parental awareness, attitude and behavior towards vaccination.     

Assessment of thyroiditis risk associated with HPV vaccination among girls aged 9–18 years: A time-varying cohort study

BackgroundPrevious studies have suggested a relationship between human papillomavirus vaccine and autoimmune diseases, including thyroiditis. Thus, we aimed to evaluate the risk of thyroiditis associated with HPV vaccination among girls using the Primary Care Database For Pharmacoepidemiological Research (BIFAP) in Spain.MethodsIn this retrospective cohort study, girls in BIFAP aged 9–18 years from 2007 to 2016, free of past thyroiditis and HPV vaccination, were included. Hazard Ratios (HRs; 95% CI) of thyroiditis were calculated within exposed periods (up to 2 years of vaccination) and post-exposed periods (from 2 years after vaccination onwards) compared with non-exposed periods, overall, by dose and by type of vaccine, adjusted for potential confounders collected at different times. In a post-hoc analysis, we moved back the thyroiditis date (30 days) as a theoretical delay in diagnosis.ResultsOut of the 388,411 girls included in the cohort, 153,924 were vaccinated against HPV and 480 thyroiditis (253 autoimmune) cases were identified (334 non-exposed; 103 exposed; 43 post-exposed). Adjusted HR was 1.18 [95% CI: 0.79–1.76] for exposed (1.25 [0.77–2.04] for bi- and 1.15 [0.76–1.76] for quadri-valent vaccines) and 1.26 [0.74–2.14] for post-exposed periods. HR was 1.50 [0.87–2.59] for the 1^st dose, 1.13 [0.66–1.91] for the 2^nd and 1.11 [0.71–1.72] for the 3^rd one. When the diagnosis date was moved back, the risk was 1.14 [0.76–1.70] for exposed period, being 1.80 [0.86–3.76] and 1.40 [0.74–2.66] after 1^st dose of bi- and quadri-valent, respectively.ConclusionsWe did not observe an increased risk of thyroiditis following HPV vaccination (whether bi- or quadri-valent). Even though the point estimate was higher after 1^st HPV vaccination dose than after subsequent doses, a dose–effect was not confirmed. Results remained similar after applying a lag time.     

Post-vaccination HPV seroprevalence among female sexual health clinic attenders in England

BackgroundThe National HPV Immunisation Programme was introduced in England in September 2008 using the HPV16/18 bivalent vaccine. We conducted serological surveillance to explore vaccination coverage levels. We also conducted a case-control study to investigate a hypothesised cross-protective effect of the HPV16/18 vaccine against genital warts.MethodsResidual serum specimens from 16 to 20 year-old women attending six specialist sexual health services (SSHS) between 2011 and 2015 in England were tested for antibodies against HPV16 and HPV18 using a virus-like particle (VLP)-based multiplex serology assay. Patients were classified as having vaccine-induced seropositivity if they were seropositive for both HPV types and either had high antibody levels for at least one HPV type, or moderately high levels for both HPV types.Differences in vaccine-induced seropositivity by patient characteristics were investigated using logistic regression. Vaccine-induced seropositivity was then compared for patients with genital warts (cases) and matched patients without (controls).ResultsOf 3,973 serum specimens collected, 3,870 (97.4%) had a valid result. The proportion of women with vaccine-induced seropositivity decreased with age (from 78.1% in 16-year-olds to 52.6% in 20-year-olds). Vaccine-induced seropositivity was lower among women born outside the UK, from more deprived areas and with a history of chlamydia diagnosis. A difference in uptake by ethnic group was also seen but this was largely confounded by differences in deprivation and country of birth. Among 537 cases and 1,515 controls, there was little evidence of a protective effect of the bivalent HPV vaccine against genital warts (adjusted odds ratio 0.93; 95% CI: 0.74–1.18).DiscussionVaccine-induced seropositivity in this high-risk population was in line with vaccination coverage in the general population although was lower in some at-risk sub-groups. This study does not provide evidence to support a cross-protective effect of the HPV16/18 vaccine against genital warts.     

Efficacy of quadrivalent human papillomavirus vaccine against persistent infection and genital disease in Chinese women: A randomized,placebo-controlled trial with 78-month follow-up

BackgroundA quadrivalent human papillomavirus vaccine (qHPV; HPV6/11/16/18) has demonstrated efficacy and effectiveness worldwide. We report qHPV vaccine efficacy for up to 6.5 years after first administration among Chinese women 20–45 years of age.MethodsIn this randomized, double-blind, placebo-controlled, multicenter, Phase 3 study (NCT00834106), women were randomized 1:1 to receive 3 doses of qHPV vaccine or placebo (Day 1, Month 2, Month 6). Endo-ecto-cervical and external genital swabs were collected for HPV testing and gynecologic examinations, and cervical cytology testing were performed at Day 1 and Months 7, 12, 18, 24, 30, 42, 54, 66, and 78. Any abnormality in cytology testing would trigger colposcopy examination and cervical biopsy, if necessary. Efficacy against genital disease, persistent infection, and the composite endpoint was assessed. Primary efficacy analyses were conducted in the per-protocol efficacy (PPE) population.ResultsOf 3006 participants randomized, 2759 (91.8%) and 2374 (79%) completed the Month 30 and Month 78 visits, respectively. At Month 78, efficacy among women aged 20–45 years was 100% (95% CI: 32.3, 100; 0 vs 7 cases) and 100% (95% CI: 70.9, 100; 0 vs 14 cases) against HPV16/18-related cervical intraepithelial neoplasia Grade 2 or 3, adenocarcinoma in situ, and cervical cancer (CIN 2+) and HPV6/11/16/18-related CIN 1+, respectively, in the PPE population. The efficacy against cervical 6-month and 12-month persistent infection was 91.6% (95% CI: 66.0, 99.0) and 97.5% (95% CI: 85.1, 99.9) at Month 30 and Month 78, respectively, in the PPE population. The vaccine also reduced the rate of cervical cytology abnormalities associated with HPV6/11/16/18, with an efficacy of 94.0% (95% CI: 81.5, 98.8). The vaccine was generally well tolerated (reported separately).ConclusionThe qHPV vaccine is efficacious against endpoints of persistent infection and genital precancerous lesions in Chinese women aged 20–45 years.     

Association between health insurance coverage and uptake of seasonal influenza vaccine in Brazos County,Texas

BackgroundLack of health insurance may limit access to influenza vaccination, resulting in higher risk of infection.MethodsThe Brazos County Health Department obtained medical records summarizing vaccination and health insurance status of all influenza cases occurring in December 2017 (n = 417). The odds of influenza vaccination were estimated for those with public or private health insurance as compared to uninsured individuals using multivariate logistic regression analysis adjusted for age and race.ResultsHealth insurance coverage among Brazos County residents with influenza was 62.4%. Public and private health insurance was associated with higher odds of influenza vaccination compared to no insurance (aOR: 2.05; 95% CI: 1.00–4.21 and aOR: 1.77; 95% CI: 1.07–2.92, respectively), particularly among adults 18–64 years of age.ConclusionsInfluenza vaccination is strongly associated with health insurance. Expansion of programs that facilitate access to health services or provide free influenza vaccines may improve influenza prevention among the uninsured.     

Reduction of HPV16/18 prevalence in young women after eight years of three- and two-dose vaccination schemes

BackgroundRecommendations for human papillomavirus vaccination have relied on immunogenicity studies and efficacy results derived from adult women. Insufficient information exists regarding HPV effectiveness in vaccinated girls as they become sexually active, regardless of dose scheme. We aimed to compare the prevalence of high-risk HPV between unvaccinated and vaccinated young women eight years after immunization.MethodsAfter eight years, we recontacted women who received two-dose of bivalent or three-dose—either bivalent or quadrivalent—, HPV vaccine when aged 9–10 years-old as part of a clinical trial. Additionally, we recruited a contemporaneous unvaccinated woman group for comparison. Only those sexually active were included. High-risk HPV DNA was determined in urine samples and compared across groups.ResultsThe prevalence of HPV16/18 types was 6.8% (95 %CI 3.2–14.1%) in the unvaccinated (n = 6/88), 1.1% (95 %CI 0.2–5.8%) in the three-dose (n = 1/93), and 0.0% (95 %CI 0.0–7.0%) in the two-dose group (n = 0/51).ConclusionHPV vaccination, with two-dose of bivalent or three-dose schemes—either with the bivalent or quadrivalent vaccine—, was associated with a lower prevalence of HPV16/18 types eight years after primary immunization.     

Systematic literature review of cross-protective effect of HPV vaccines based on data from randomized clinical trials and real-world evidence

BackgroundThe extent of cross-protection provided by currently licensed bivalent and quadrivalent HPV vaccines versus direct protection against HPV 31-, 33-, 45-, 52-, and 58-related disease is debated. A systematic literature review was conducted to establish the duration and magnitude of cross-protection in interventional and observational studies.MethodsPubMed and Embase databases were searched to identify randomized controlled trials (RCT) and observational studies published between 2008 and 2019 reporting on efficacy and effectiveness of HPV vaccines in women against non-vaccine types 31, 33, 45, 52, 58, and 6 and 11 (non-bivalent types). Key outcomes of interest were vaccine efficacy against 6- and 12-month persistent infection or genital lesions, and type-specific genital HPV prevalence or incidence. RCT data were analyzed for the according-to-protocol (bivalent vaccine) or negative-for-14-HPV-types (quadrivalent vaccine) efficacy cohorts.ResultsData from 23 RCTs and 33 observational studies evaluating cross-protection were extracted. RCTs assessed cross-protection in post-hoc analyses of small size subgroups. Among fully vaccinated, baseline HPV-naïve women, the bivalent vaccine showed statistically significant cross-protective efficacy, although with wide confidence intervals, against 6-month and 12-month persistent cervical infections and CIN2+ only consistently for HPV 31 and 45, with the highest effect observed for HPV 31 (range 64.6% [95% CI: 27.6 to 83.9] to 79.1% [97.7% CI: 27.6 to 95.9] for 6-month persistent infection; maximal follow-up 4.7 years). No cross-protection was shown in extended follow-up. The quadrivalent vaccine efficacy reached statistical significance for HPV 31 (46.2% [15.3–66.4]; follow-up: 3.6 years). Similarly, observational studies found consistently significant effectiveness only against HPV 31 and 45 with both vaccines.ConclusionsRCTs and observational studies show that cross-protection is inconsistent across non-vaccine HPV types and is largely driven by HPV 31 and 45. Furthermore, existing data suggest that it wanes over time; its long-term durability has not been established.     

Validation of parental reports of rotavirus vaccination of their children compared to the national immunization registry

BackgroundThe introduction of rotavirus vaccines into national immunization programs necessitates vaccine effectiveness evaluations. Parental report of vaccination status is a simple and accessible source of information; however, its validity is unclear.AimsTo validate parental reports of rotavirus immunization compared to documentation of vaccination in national immunization registry, and to assess vaccine effectiveness by each method.MethodsParents of 1272 children aged 2–59 months from northern Israel hospitalized for gastroenteritis in 2011–2015 were interviewed on the sociodemographics and rotavirus vaccination status of their child. Rotavirus immunization status based on parental report was compared to that documented in the national immunization registry, which was considered the gold standard. Stool samples collected from patients were tested for rotavirus antigen by immunochromotgraphy. In a rotavirus test-negative case-control study, vaccination history was compared between children found positive for rotavirus and those who tested negative. Vaccine effectiveness for ≥ 1 dose vs. zero doses was calculated as: (1-adjusted odds ratio) * 100.ResultsThe sensitivity and specificity of parental report of their child's immunization with a rotavirus vaccine were 97% (95% CI 96–98), and 75% (95% CI 65–82), respectively. Kappa coefficient was 0.69 (p < 0.001) for the agreement between the two methods. Rotavirus vaccine effectiveness was 72% (95% CI 54–84) when using parental report of rotavirus immunization and 79% (95% CI 62–88) when using the registry.ConclusionParental report of their child's immunization with a rotavirus vaccine demonstrated high sensitivity, although the specificity was relatively low. Vaccine effectiveness was similar regardless of method used to determine rotavirus immunization status. Parental report of vaccination status can be useful in vaccine effectiveness assessment.     

Pre-implementation evaluation for an HPV vaccine provider communication intervention among primary care clinics

ObjectivesInterventions to improve health care provider communication about HPV vaccination can increase vaccine acceptance. Our objectives were to (1) identify clinics in locations with high HPV-associated cancer and low HPV-vaccination rates that would potentially benefit from dissemination of a proposed HPV Provider Communication intervention and (2) use qualitative interviews and a dissemination and implementation framework to assess readiness for change and fit of the HPV Provider Communication intervention to the context of these clinics.MethodsLocal HPV-associated cancer and HPV vaccination rates were assigned to Practice-Based Research Network clinics using data from the Colorado Central Cancer Registry, the Colorado Immunization Information System, and the American Community Survey. Staff from 38 clinics located in areas with high numbers of adolescents not up-to-date for HPV vaccine and high rates of HPV-associated cancers were recruited for qualitative interviews. Interview questions used the Promoting Action on Research Implementation in Health Services (PARIHS) conceptual framework and addressed the proposed intervention, current vaccination practices and prior quality improvement (QI) experience.ResultsTwenty-seven interviews were completed with clinicians, clinic managers, and other staff across 17 clinics (9 pediatric, 5 family medicine, 3 public/school-based health). Most clinics had some prior QI experience and there were few thematic differences between sites with more or less foundation for QI/immunization work. Participants were motivated to improve the health of their patients and valued both guidelines and local experience as important evidence to consider adopting an intervention. Interviewees were more interested in implementing the proposed intervention if it aligned with existing priorities and fit within clinic workflows. Facilitation needs included adequate time and external facilitation support for data tracking and analysis.ConclusionsQualitative interviews to understand clinic context and fit of an HPV Provider Communication intervention can inform implementation in settings with the highest potential for clinical impact.     

Human papillomavirus vaccine coverage in Rwanda: A population-level analysis by birth cohort

BackgroundIn 2011, Rwanda became the first African nation to implement a national human papillomavirus (HPV) vaccination program, conceived to protect girls aged <15 years (i.e. born ≥1997). After an initial school-grade-targeted catch-up campaign, there was a transition to routine vaccination of 12 year-olds only. We aimed to produce population-level vaccine coverage estimates.MethodsThe Rwandan Expanded Program on Immunization (EPI) collected data on number of eligible girls and HPV vaccines delivered, stratified by calendar year (2011–2018), girl’s age, district and vaccination round. HPV vaccine coverage was estimated by birth cohort (reconstituted using calendar year and age), as a proportion of (1) eligible target, and (2) the 2012 Rwandan census population.Results1,156,863 girls received first dose of HPV vaccine between 2011 and 2018, corresponding to 98% of the eligible target. Median vaccination age was 15 years (interquartile range [IQR] 13–16) in 2011–2013 (school grade-targeted catch-up), 13 years (IQR 12–14) in 2014 (transition) and 12 years in 2015–2018 (routine). Population-level coverage versus the census increased from 10 to 40% for girls born in 1993–1995 (median vaccination age = 17 years) to 50–65% for 1996–2000 birth cohorts (14 years), and 80–90% for 2001–2006 birth cohorts (12 years). Coverage trends were similar across provinces and in the capital, Kigali. Second and third round coverage suggested most vaccinated girls completed their recommended dosing regimen (which reduced from 3 to 2 doses in 2015).ConclusionsBirth cohorts provide a clear picture of population-level HPV vaccine coverage after a pragmatic catch-up campaign, particularly in Rwanda where eligible school grades included wide age ranges. Whilst the catch-up campaign resulted in some coverage gaps in out-of-school teenagers, coverage remains high in cohorts routinely targeted as 12 year-olds.