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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

Risk factors of ICU or high dependency requirements amongst hospitalized pediatric pertussis cases: A 10 year retrospective series,Singapore

IntroductionPertussis causes the highest complication rates and deaths in the infant group. Our study explored risk factors for ICU/high dependency (HD) admissions and intubation/non-invasive ventilation (NIV).MethodsA retrospective review of pertussis admissions over 10 years from 2007 to 2016 was done at KK Women's and Children's Hospital, Singapore. To understand risk factors for severe pertussis infection, we compared cases requiring ICU/HD care with controls admitted to the general ward. Risk factors for intubation/NIV were also studied. Vaccine efficacy for protection against ICU/HD admission or intubation/NIV was also calculated.ResultsThere were 200 pertussis patients with a median age of 2.75 months. Sixty-one % were ≤3 months and 14.5% were <6 weeks old. Majority of patients (77%) had no prior pertussis vaccination. After removing 3 patients with missing vaccination records, 20 cases were compared with 177 controls. On univariate analysis, risk factors for ICU/HD admission comprised: Age ≤3 months, contact history, underlying co-morbidity, prematurity, absent DTaP vaccination, lymphocytosis, hyperleukocytosis (wbc ≥50 × 10⁹/L), thrombocytosis (platelet ≥500 × 10⁹/L), and pneumonia. Multivariate analysis revealed that age ≤3 months (OR 40, 95% CI 4.57–1111.11, p = .007), co-morbidity (OR 8.46 (95% CI 1.47–56.89, p = .019), pneumonia (OR 18.08, 95% CI 3.22–132.15, p = .002), white cell count (OR 1.07, 95% CI 1.01–1.14, p = .023) and cyanosis (OR 5.09, 95% CI 1.31–24.71, p = .026) were risk factors for ICU/HD admission. Prior DTaP vaccination had a vaccine effectiveness of 86.5% in preventing ICU/HD admission and 82.1% in preventing intubation/NIV.ConclusionsAs the majority of pertussis patients were infants ≤3 months old who are at high risk for ICU/HD admission and intubation/NIV, prevention is key to reducing pertussis morbidity. Even though not statistically significant, DTaP vaccination had a role in preventing ICU/HD admission and intubation/NIV.     

Parental perceptions of childhood seasonal influenza vaccination in Singapore: A cross-sectional survey

PurposeSeasonal influenza vaccination is recommended in children aged 6–59 months, but little is known about child vaccination coverage and determinants in Asian settings. We report the results of a survey of knowledge, attitudes, practices, and determinants of child influenza vaccination in Singapore.MethodsIn December 2015-March 2016, we conducted a survey of 332 parents of children aged 6 months to 5 years attending pre-schools. We assessed child influenza vaccine coverage and parental knowledge, attitudes, and practices of child influenza vaccination. We used multivariable regression and structural equation models to identify factors associated with child influenza vaccination.ResultsKnowledge about influenza, perceived benefit of vaccination, and willingness to vaccinate were high. However, only 32% of children had ever received influenza vaccine, and only 15% in the past year. Factors independently associated with child influenza vaccination included: being recommended influenza vaccine by a child’s doctor (prevalence ratio (PR) = 2.47, 95% CI: 1.75–3.48); receiving influenza vaccine information from a private general practitioner (PR = 1.47, 95% CI: 1.05–2.04); regularly receiving pre-travel influenza vaccine (PR = 1.64, 95% CI: 1.19–2.25); higher willingness to vaccinate (PR = 1.58, 95% CI:1.24–2.04 per unit increase in willingness score); and feeling well-informed about influenza vaccine (PR = 1.44, 95% CI: 1.04–1.99). Parents who obtained influenza vaccine information from television were less likely to have vaccinated their child (PR = 0.44, 95% CI: 0.23–0.85). Path analysis indicated that being recommended vaccination by a child's doctor increased willingness to vaccinate and self-efficacy (feeling well-informed about influenza vaccine). Median willingness-to-pay for a dose of influenza vaccine was SGD30 (interquartile range: SGD20-SGD50), and was higher in parents of vaccinated compared with unvaccinated children (SGD45 vs SGD30, p = 0.0012).ConclusionKnowledge and willingness to vaccinate was high in this parent population, but influenza vaccine uptake in children was low. Encouraging medical professionals to recommend vaccination of eligible children is key to improving uptake.     

Pneumococcal vaccination: Direct and herd effect on carriage of vaccine types and antibiotic resistance in Icelandic children

BackgroundSince the introduction of pneumococcal conjugate vaccines, vaccine type pneumococcal carriage and disease has decreased world-wide. The aim was to monitor changes in the nasopharyngeal carriage of pneumococci, the distribution of serotypes and antimicrobial resistance in children before and after initiation of the 10-valent pneumococcal vaccination in 2011, in a previously unvaccinated population.MethodsRepeated cross-sectional study at 15 day-care centres in greater Reykjavik area. Nasopharyngeal swabs were collected yearly in March from 2009 to 2015. The swabs were selectively cultured for pneumococci, which were serotyped using latex agglutination and/or PCR and antimicrobial susceptibility determined. Two independent studies were conducted.In study 1, on total impact, isolates from children aged <4 years were included. The vaccine-eligible-cohort (birth-years: 2011–2013, sampled in 2013–2015) was compared with children at the same age born in 2005–2010 and sampled in 2009–2012. In study 2 on herd effect, isolates from older non-vaccine-eligible children (3.5–6.3 years) were compared for the periods before and after the vaccination (2009–2011 vs 2013–2015. Vaccine impact was determined using 1-odds-ratio.ResultsFollowing vaccination, the vaccine impact on vaccine type acquisition was 94% (95% CI: 91–96%) in study 1 and 56% (95% CI: 44–65%) in study 2. The impact on serotype 6 A was 33% (95% CI: −9%; 59%) in study 1 and 42% (95% CI: 10–63%) in study 2 with minimal effect on 19A. The non-vaccine serotypes/groups 6C, 11, 15 and 23B were the most common serotypes/groups after vaccination. Isolates from the vaccine-eligible-cohort had lower penicillin MICs, less resistance to erythromycin and co-trimoxazole and less multi resistance than isolates from the control-group.ConclusionsThe efficacy of the vaccination on vaccine serotypes was high, and a milder effect on vaccine-associated-serotype 6A was observed for the vaccine-eligible-cohort. There was a significant herd effect on vaccine types in older non-vaccine-eligible children. Overall antimicrobial non-susceptibility was reduced.     

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.