Annika M. Hofstetter

Vaccination of special populations: Protecting the vulnerable.

One of the strategic objectives of the 2011-2020 Global Vaccine Action Plan is for the benefits of immunisation to be equitably extended to all people. This approach encompasses special groups at increased risk of vaccine-preventable diseases, such as preterm infants and pregnant women, as well as those with chronic and immune-compromising medical conditions or at increased risk of disease due to immunosenescence. Despite demonstrations of effectiveness and safety, vaccine uptake in these special groups is frequently lower than expected, even in developed countries with vaccination strategies in place. For example, uptake of the influenza vaccine in pregnancy rarely exceeds 50% in developed countries and, although data are scarce, it appears that only half of preterm infants are up-to-date with routine paediatric vaccinations. Many people with chronic medical conditions or who are immunocompromised due to disease or aging are also under-vaccinated. In the US, coverage among people aged 65years or older was 67% for the influenza vaccine in the 2014-2015 season and 55-60% for tetanus and pneumococcal vaccines in 2013, while the coverage rate for herpes zoster vaccination among those aged 60years or older was only 24%. In most other countries, rates are far lower. Reasons for under-vaccination of special groups include fear of adverse outcomes or illness caused by the vaccine, the inconvenience (and in some settings, cost) of vaccination and lack of awareness of the need for vaccination or national recommendations. There is also evidence that healthcare providers attitudes towards vaccination are among the most important influences on the decision to vaccinate. It is clear that physicians adherence to recommendations needs to be improved, particularly where patients receive care from multiple subspecialists and receive little or no care from primary care providers.

Human Papillomavirus Vaccination and Cervical Cytology Outcomes Among Urban Low-Income Minority Females

IMPORTANCEnThe quadrivalent human papillomavirus (HPV) vaccine was licensed for use in 9- through 26-year-old females in 2006. Postlicensure studies in Australia, Denmark, and Canada have demonstrated vaccine effectiveness against abnormal cervical cytology results. However, there are limited data describing postlicensure effectiveness in the United States, particularly among minority females at higher risk for HPV infection and cervical cancer.nnnOBJECTIVEnTo examine the effect of HPV vaccination on abnormal cervical cytology results among minority females.nnnDESIGN, SETTING, AND PARTICIPANTSnRetrospective cohort study conducted between January 2007 and January 2014 at 16 academically affiliated community clinics serving a low-income minority population. Included in this study was a population-based sample of 16u202f266 females aged 11 through 20 years as of January 1, 2007, who received care at a participating clinic on or after that date.nnnEXPOSUREnHuman papillomavirus vaccination, stratified by the number of doses.nnnMAIN OUTCOMES AND MEASURESnCervical cytology abnormality following either HPV vaccination or, if unvaccinated, the first missed opportunity for HPV vaccination after January 1, 2007. Abnormalities were defined as atypical glandular cells, atypical squamous cells of undetermined significance, atypical squamous cells, cannot exclude a high-grade squamous intraepithelial lesion, low-grade squamous intraepithelial lesions, or high-grade squamous intraepithelial lesions.nnnRESULTSnThere were 4127 female patients who initiated quadrivalent HPV vaccination or had their first missed HPV vaccination opportunity from 11 through 20 years of age and underwent subsequent cervical cytology screening. The patients were primarily Spanish speaking (nu2009=u20092297; 58.3%) and publicly insured (nu2009=u20093801; 92.1%). The detection rate for an abnormal cervical cytology result during the observation period was lower among vaccinated (≥1 dose) (79.1 per 1000 person-years) vs unvaccinated (125.7 per 1000 person-years) females. The risk for an abnormal cervical cytology result was lower among vaccinated vs unvaccinated females (hazard ratio [HR], 0.64; 95% CI, 0.57-0.73), particularly if the 3-dose series was completed (HR, 0.48; 95% CI, 0.41-0.56) or if the vaccine was administered from 11 through 14 years of age (≥1 dose: HR, 0.36; 95% CI, 0.16-0.79; 3 doses: HR, 0.27; 95% CI, 0.12-0.63). This protective effect remained after adjusting for demographics, clinic type, abnormal baseline cervical cytology result, and baseline Chlamydia screening (as proxy for sexual experience).nnnCONCLUSIONS AND RELEVANCEnThis study demonstrated the HPV vaccine is effective in a real-world setting of high-risk patients with variable HPV vaccination patterns.

Clinician-parent discussions about influenza vaccination of children and their association with vaccine acceptance

OBJECTIVEnTo examine how clinicians communicate with parents about influenza vaccination and the effect of these communication behaviors on parental vaccine decision-making.nnnSTUDY DESIGNnWe performed a secondary analysis of data obtained from a cross-sectional observational study in which health supervision visits between pediatric clinicians and English-speaking parents of young children were videotaped. Eligible visits occurred during the 2011-2012 and 2013-2014 influenza seasons, included children ≥6months, and contained an influenza vaccine discussion. A coding scheme of 10 communication behaviors was developed and applied to each visit. Associations between clinician communication behaviors and parental verbal vaccine acceptance and parental visit experience were examined using bivariate analysis and generalized linear mixed models.nnnRESULTSnFifty visits involving 17 clinicians from 8 practices were included in analysis. The proportion of parents who accepted influenza vaccine was higher when clinicians initiated influenza vaccine recommendations using presumptive rather than participatory formats (94% vs. 28%, p<0.001; adjusted odds ratio 48.2, 95% CI 3.5-670.5). Parental acceptance was also higher if clinicians pursued (vs. did not pursue) original recommendations when parents voiced initial resistance (80% vs. 13%, p<0.05) or made recommendations for influenza vaccine concurrent with (vs. separate from) recommendations for other vaccines due at the visit (83% vs. 33%, p<0.01). Parental visit experience did not differ significantly by clinician communication behaviors.nnnCONCLUSIONnPresumptive initiation of influenza vaccine recommendations, pursuit in the face of resistance, and concurrent vaccine recommendations appear to increase parental acceptance of influenza vaccine without negatively affecting visit experience.

Human Papillomavirus Vaccination of Adolescents with Chronic Medical Conditions: A National Survey of Pediatric Subspecialists

STUDY OBJECTIVEnMany adolescents with chronic medical conditions (CMCs) are at risk of human papillomavirus (HPV) infection, associated complications, and underimmunization and often identify a pediatric subspecialist as their main provider. This study aimed to assess the HPV-related understanding, beliefs, and practices of pediatric subspecialists, which are largely unknown.nnnDESIGN AND SETTINGnNational cross-sectional study.nnnPARTICIPANTSnPediatric endocrinologists, hematologist/oncologists, pulmonologists, and rheumatologists identified using the American Medical Association Physician Masterfile (n = 418).nnnINTERVENTIONSnSubspecialists who care for adolescents with CMCs in the outpatient setting were recruited to complete a Web-based survey on their HPV-related knowledge, attitudes, comfort, and practices.nnnMAIN OUTCOME MEASURESnHPV vaccination recommendation.nnnRESULTSnOver half of respondents (50.4%; n = 196/389)xa0reported sometimes or always recommending HPV vaccination to adolescent patients with CMCs. Factors positively associated with recommendation included hematology/oncology (adjusted odds ratio [AOR], 4.69; 95% confidence interval [CI], 1.86-11.81) or rheumatology (AOR, 6.55; 95% CI, 1.67-25.74) specialization, seeing more adolescent patients with CMCs (AOR, 1.01; 95% CI, 1.00-1.02), and sometimes or always discussing sexual health (AOR, 2.53; 95% CI, 1.05-6.08) or checking vaccine status (AOR, 3.83; 95% CI, 1.59-9.20) with these patients. Those who thought it was important, but were uncomfortable discussing sexual health when recommending HPV vaccination (AOR, 0.28; 95% CI, 0.12-0.70) or who reported insufficient HPV vaccine information (AOR, 0.45; 95% CI, 0.23-0.88) or lack of primary-subspecialty care provider communication (AOR, 0.38; 95% CI, 0.16-0.93) as barriers to HPV vaccination were less likely to recommend HPV vaccination.nnnCONCLUSIONnThis study revealed that many subspecialists fail to recommend HPV vaccination to adolescents with CMCs and highlights potential targets for future interventions.

Risk of Rotavirus Nosocomial Spread After Inpatient Pentavalent Rotavirus Vaccination

This study assesses RV5 coverage, shedding of wild-type and vaccine-type rotavirus strains, and nosocomial transmission among infants hospitalized in an intensive care setting. BACKGROUND: Infants born prematurely or with underlying conditions are at increased risk of severe rotavirus disease and associated complications. Given the theoretical risk of nosocomial transmission of vaccine-type rotavirus, rotavirus vaccination is recommended for infants at or after discharge from neonatal care settings. Because the first dose should be administered by 104 days of age, some infants may be age-ineligible for vaccination if delayed until discharge. METHODS: This prospective cohort included infants admitted to an urban academic medical center between birth and 104 days who received care in intensive care settings. Pentavalent human-bovine reassortant rotavirus vaccine (RV5) was used, per routine clinical care. Stool specimens were collected weekly (February 2013–April 2014) and analyzed for rotavirus strains using real-time reverse transcription–polymerase chain reaction. Demographic and vaccine data were collected. RV5 safety was not assessed. RESULTS: Of 385 study infants, 127 were age-eligible for routine vaccinations during hospitalization. At discharge, 32.7% were up-to-date for rotavirus vaccination, compared with 82.7% for other vaccinations. Of rotavirus-unvaccinated infants, 42.6% were discharged at age >104 days and thus vaccination-ineligible. Of 1192 stool specimens collected, rotavirus was detected in 13 (1.1%): 1 wild-type strain from an unvaccinated infant; 12 vaccine-type strains from 9 RV5-vaccinated infants. No vaccine-type rotavirus cases were observed among unvaccinated infants (incidence rate: 0.0 [95% confidence interval: 0.0–1.5] cases per 1000 patient days at risk). CONCLUSIONS: These data suggest that delaying rotavirus vaccination until discharge from the hospital could lead to missed vaccination opportunities and may be unnecessary in institutions using RV5 with comparable infection control standards.

Parental Vaccine Hesitancy and Declination of Influenza Vaccination Among Hospitalized Children

OBJECTIVESnParents frequently decline the influenza vaccine for their child during hospitalization. In this study, we aimed to assess the role of vaccine hesitancy in these declinations.nnnMETHODSnThis cross-sectional survey study was conducted among English-speaking parents of influenza vaccine-eligible children who were hospitalized between October 2014 and April 2015. Between July 2015 and September 2015, parents were recruited via mail to complete the validated Parent Attitudes about Childhood Vaccines (PACV) survey (modified for influenza vaccination). PACV scores (0-100 scale) were dichotomized into scores of ≥50 (hesitant) and <50 (nonhesitant). The primary outcome was parental declination of the influenza vaccine for their child during hospitalization. A secondary outcome was the declination reason documented during hospitalization. The main independent variable was parental vaccine hesitancy status, determined by the PACV score. Multivariable logistic regression was used to examine the association between vaccine hesitancy and influenza vaccine declination, adjusting for sociodemographic, visit, and clinical characteristics. The relationship between vaccine hesitancy and declination reason was also explored.nnnRESULTSnOf 199 parents (18% response rate), 24% were vaccine hesitant and 53% declined the influenza vaccine for their child during hospitalization. Vaccine hesitancy (versus nonhesitancy) was associated with declining influenza vaccination (adjusted odds ratio: 6.4; 95% confidence interval: 2.5-16.5). The declination reason differed by vaccine hesitancy status, with a higher proportion of parents who were hesitant versus nonhesitant reporting vaccine concern or vaccine unnecessary.nnnCONCLUSIONSnVaccine hesitancy was prevalent in this limited sample of parents of hospitalized children and associated with influenza vaccine declination. Additional investigation in a large, diverse, prospectively recruited cohort is warranted given the potential sampling bias present in this study.

Outreach and Reminders to Improve Human Papillomavirus Vaccination in an Integrated Primary Care System

This study evaluated the impact of health system–based outreach and reminders on human papillomavirus (HPV) vaccine series initiation and completion. Parents of 10 to 12 year olds (n = 1805) were randomized to receive either (1) an outreach letter and brochure recommending HPV vaccination followed by automated HPV vaccine reminders or (2) usual care. We interviewed a subset of 50 parents to assess program acceptability. Outcomes were HPV vaccine initiation during the study period and on-time series completion. Rates of HPV vaccine initiation during the study period (July 2015 to August 2016) were similar between the intervention and control groups, but initiation within 120 days of randomization was higher in the intervention group (23.6% and 18.8%, P = .04) as was completion during the study period (10.3% vs 6.8%, P = .04). Reminders for doses 2 and 3 did not affect completion. The program was acceptable to parents. This study provides evidence that health system–based outreach and reminders can improve HPV vaccination.

Text message reminders for vaccination of adolescents with chronic medical conditions: A randomized clinical trial

BACKGROUNDnMany adolescents with chronic medical conditions (CMCs) are at risk of vaccine-preventable infection, yet are frequently under-vaccinated. Text message reminders, particularly those with embedded educational information, have been shown to increase general pediatric vaccination. Their use has not been studied specifically among adolescents with CMCs.nnnMETHODSnEligible parents of adolescents with CMCs receiving care at one of 4 academically-affiliated pediatric clinics and requiring human papillomavirus (first dose), influenza, and/or pneumococcal polysaccharide vaccines were randomized in 4 consecutive cohorts to receive text message vaccine reminders with or without embedded educational information (educational vs. plain arm, respectively). Educational reminders, including one interactive message, addressed infection risk, vaccine safety/efficacy, and physician recommendations. Up to 5 weekly and 2 booster reminders were sent (October 2014-January 2015). Receipt of any needed vaccine and missed vaccination opportunities by 4, 12, and 24weeks after the initial reminder were compared between arms.nnnRESULTSnOf randomized parents (n=295), 175 (59.3%) were Spanish-speaking; most had adolescents with CMCs who were 13-17years (n=229; 77.6%) and publically insured (n=272; 92.5%). Baseline demographics and parental vaccine beliefs were similar between arms. More adolescents in the plain vs. educational reminder arm received any needed vaccine by 4weeks (31.9% vs. 22.7%, adjusted relative risk [aRR] 1.47, 95% CI 1.01-2.14), but not by 12 or 24weeks. Plain reminders were noted in post hoc analyses to have a greater effect than educational reminders in certain sub-populations, including 11-12year-olds and those sent the initial reminder in early fall. Fewer adolescents in the plain vs. educational reminder arm had a missed vaccination opportunity by 4weeks (10.9% vs. 41.3%; aRR 0.21, 95% CI 0.07-0.60), but not by 12 or 24weeks.nnnCONCLUSIONnPlain text message vaccine reminders appear to have a positive effect compared to educational ones in the short-term and for certain families.nnnTRIAL REGISTRATIONnNCT02231957 (www.clinicaltrials.gov).

RSV Hospitalizations in Comparison With Regional RSV Activity and Inpatient Palivizumab Administration, 2010–2013

OBJECTIVESnTo compare pediatric respiratory syncytial virus (RSV) hospitalizations in the United States to regional RSV activity and inpatient palivizumab administration.nnnMETHODSnWe characterized inpatients, excluding newborns, with RSV from the Pediatric Health Information System (July 2010-June 2013). RSV regional activity timing was defined by the National Respiratory and Enteric Virus Surveillance System. RSV hospitalization season (defined by at least 3 SDs more than the mean regional baseline number of RSV hospitalizations for 3 consecutive weeks) was compared with RSV regional activity season (2 consecutive weeks with ≥10% RSV-positive testing). Logistic regression was used to determine predictors of hospitalization timing (ie, during or outside of regional activity season). We also assessed the timing of inpatient palivizumab administration.nnnRESULTSnThere were 50u2009157 RSV hospitalizations. Mean RSV hospitalization season onset (early November) was 3.3 (SD 2.1) weeks before regional activity season onset (early December). Hospitalization season offset (early May) was 4.4 (SD 2.4) weeks after activity season offset (mid-April). RSV hospitalization and activity seasons lasted 18 to 32 and 13 to 23 weeks, respectively. Nearly 10% of hospitalizations occurred outside of regional activity season (regional ranges: 5.6%-22.4%). Children with chronic conditions were more likely to be hospitalized after regional activity season, whereas African American children were more likely to be hospitalized before. Inpatient palivizumab dosing was typically initiated before the start of RSV hospitalizations.nnnCONCLUSIONSnThere is regional variation in RSV hospitalization and activity patterns. Many RSV hospitalizations occur before regional activity season; high-risk infants may require RSV immunoprophylaxis sooner.

Vaccination Coverage of Adolescents With Chronic Medical Conditions

INTRODUCTIONnAdolescents with chronic medical conditions (CMCs) are at increased risk of vaccine-preventable infections. Little is known about their vaccine uptake.nnnMETHODSnThis retrospective cohort study included 3,989 adolescents aged 11-17 years receiving care at academically affiliated pediatric clinics between August 2011 and June 2013. Data were abstracted from the medical centers electronic health record and immunization registry in 2014. Vaccination coverage, timeliness, and missed opportunities were evaluated and analyzed in 2015-2016.nnnRESULTSnAdolescents with CMCs had lower human papillomavirus vaccination initiation than those without CMCs (81.3% vs 85.0%), although this difference was only observed in stratified analysis among males (adjusted relative risk=0.90, 95% CI=0.85, 0.96), aged 13-17 years (adjusted relative risk=0.94, 95% CI=0.91, 0.98), and those with more primary care visits (adjusted relative risk=0.94, 95% CI=0.91, 0.98). Adolescents with CMCs had greater influenza vaccination coverage and timeliness than those without CMCs (2011-2012 season: 66.9% vs 50.1%; adjusted hazards ratio=1.27, 95% CI=1.15, 1.40; 2012-2013 season: 73.8% vs 64.5%; adjusted hazards ratio=1.20, 95% CI=1.10, 1.31). Only 32.1% and 18.2% of eligible adolescents had received pneumococcal polysaccharide and 13-valent pneumococcal conjugate vaccines, respectively. Missed opportunities were higher among adolescents with versus without CMCs for human papillomavirus vaccination initiation (4.2 vs 2.7, p<0.001), meningococcal vaccination (4.0 vs 2.9, p<0.001), and influenza vaccination (2011-2012 season: 2.1 vs 1.7, p<0.001; 2012-2013 season: 2.0 vs 1.6, p<0.001). Missed opportunities for pneumococcal vaccination were common.nnnCONCLUSIONSnPockets of undervaccination and missed opportunities exist among adolescents with CMCs. Greater, more timely influenza vaccination suggests that optimal vaccination of high-risk adolescents is possible.