Practice and child characteristics associated with influenza vaccine uptake in young children

Characteristics and determinants of seasonal influenza vaccination in Manitoba, Canada: A population-wide record-linkage study

Background

Seasonal influenza vaccine (SIV) uptake (receipt of vaccine) in Manitoba, Canada is consistently low notwithstanding vaccine availability and free-of-charge vaccination. Despite, there is a lack of published evidence on the determinants of uptake of the vaccine. We sought to assess the association between SIV uptake and certain population and primary care physician (PCP) characteristics in Manitoba.

Methods

We conducted a longitudinal study utilizing Manitoba administrative health databases. We summarized SIV uptake from 2000/01-2019/20 influenza seasons across subpopulations defined by socioeconomic, health-related and PCP characteristics. Utilizing multivariable generalized estimating equation logistic regression models, we assessed the association between SIV uptake and the socioeconomic, health-related and PCP characteristics, stratified by age group (<5-, 5-17-, 18-44-, 45-64-, ≥65-year-olds) and sex. Results are adjusted odds ratios with associated 95 % confidence intervals.

Results

SIV uptake percentage increased over time with 4.4 %, 13.1 %, 17.5 % and 21.7 % of < 5-year-olds, 2 %, 4.9 %, 9.7 % and 13.1 % of 5-17-year-olds, 5.4 %, 8.8 %, 10.7 % and 13.5 % of 18-44-year-olds, 16.8 %, 21.3 %, 23.6 % and 24.6 % of 45-64-year-olds receiving the SIV in 2000-2004, 2005-2009, 2010-2014 and 2015-2019, respectively. There was a decline among ≥ 65-year-olds from 58.5 % to 53.5 %. We observed a similar pattern across subpopulations. There were significantly increased odds of SIV uptake among females within the age groups ≥ 18 years, in higher income quintiles, mostly with increased contact with a PCP/hospitalization within age groups ≥ 18 years, among those who had older or female PCPs (the opposite observation among ≥ 65-year-olds) and whose PCP administered at least one SIV in prior influenza season. These observations were largely consistent irrespective of sex.

Conclusion

SIV uptake in Manitoba appears to increase with age, and many socioeconomic, health-related and PCP characteristics appear to be associated with it. These findings may inform targeted vaccination programs to optimize influenza vaccination in Manitoba and similar Canadian jurisdictions.

Influenza Vaccination Coverage Rates and Determinants in Greek Children until the Age of Ten (2008-2019), the Rhea Mother-Child Cohort

BACKGROUND

In Greece, influenza vaccination is currently recommended for children with high-risk conditions. There are limited data on influenza vaccination uptake among Greek children with and without high-risk conditions. We aim to describe the annual influenza vaccination uptake until the age of ten in a population-based mother-child cohort and identify the factors influencing vaccination rates.

METHODS

Immunization data from the child's health cards at 4 and 10 years were available for 830 and 298 children participating in the Rhea cohort (2008-2019). We calculated vaccination coverage by age, winter season and among children with asthma and obesity for whom the vaccine is indicated. Univariable and multivariable stepwise logistic regression models were utilized to identify the association between several sociodemographic, lifestyle and health-related variables and vaccine uptake by age four.

RESULTS

By the ages of four and ten, 37% and 40% of the children, respectively, had received at least one influenza vaccination. Only 2% of the children were vaccinated for all winter seasons during their first four years of life. The vaccination rate was highest at the age of two and during the 2009-2010 season. Vaccination rates for children with asthma and obesity were 18.2% and 13.3% at age four and 8.3% and 2.9% at age ten. About 10% of all vaccines were administered after December and 24% of the children received only one dose upon initial vaccination. Children with younger siblings and those who had experienced more respiratory infections were more likely to be vaccinated by the age of four, while children exposed to smoking were less likely to be vaccinated.

CONCLUSIONS

Children in our study were more likely to be vaccinated against influenza at an early age with the peak occurring at the age of two. Nonetheless, annual vaccination uptake was uncommon. Vaccination rates of children with asthma and obesity were well below the national target of 75% for individuals with chronic conditions. Certain groups may merit increased attention in future vaccination campaigns such as children raised in families with unfavourable health behaviours.

Factors Associated With COVID-19 Non-vaccination in Adolescents Hospitalized Without COVID-19

BACKGROUND

Pfizer-BioNTech COVID-19 vaccine received emergency use authorization for persons ≥ 16 years in December 2020 and for adolescents 12-15 years in May 2021. Despite the clear benefits and favorable safety profile, vaccine uptake in adolescents has been suboptimal. We sought to assess factors associated with COVID-19 non-vaccination in adolescents 12-18 years of age.

METHODS

Between June 1, 2021 and April 29, 2022, we assessed factors associated with COVID-19 non-vaccination in hospitalized adolescents ages 12-18 years enrolled in the Overcoming COVID-19 vaccine effectiveness network. Demographic characteristics and clinical information were captured through parent interviews and/or electronic medical record abstraction; COVID-19 vaccination was assessed through documented sources. We assessed associations between receipt of the COVID-19 vaccine and demographic and clinical factors using univariate and multivariable logistic regression and estimated adjusted odds ratios (aOR) for each factor associated with non-vaccination.

RESULTS

Among 1665 hospitalized adolescents without COVID-19, 56% were unvaccinated. Unvaccinated adolescents were younger (median age 15.1 years vs. 15.4 years, p < .01) and resided in areas with higher social vulnerability index (SVI) scores (median 0.6 vs 0.5, p < .001) than vaccinated adolescents. Residence in the Midwest [aOR 2.60 (95% CI: 1.80, 3.79)] or South [aOR 2.49 (95% CI: 1.77, 3.54)] US census regions, rarely or never receiving influenza vaccine [aOR 5.31 (95% CI: 3.81, 7.47)], and rarely or never taking precautions against COVID-19 [aOR 3.17 (95% CI: 1.94, 5.31)] were associated with non-vaccination against COVID-19.

CONCLUSIONS

Efforts to increase COVID-19 vaccination of adolescents should focus on persons with geographic, socioeconomic, and medical risk factors associated with non-vaccination.

Surveying Parents’ Awareness and Adherence to Influenza Vaccination Recommendations in Children in Southern Italy

Background: This study explored awareness and adhesion of parents to the recommendations for influenza vaccination for their children. Methods: This cross-sectional study was conducted from March to June 2022 among parents of 6 months–6 years-old children in Southern Italy. Results: Only 22.1% of parents were aware that influenza vaccination was recommended for healthy children, and 31.8% reported at least one influenza vaccination in the four influenza seasons from 2018/2019 to 2021/2022. Adherence was higher among parents who had received influenza vaccination at least once, who knew the main childhood vaccinations, who knew that influenza can be prevented, that influenza vaccination is recommended for healthy children, who believe that it is useful, and who have been informed about it by physicians. Willingness to vaccinate their children in the upcoming season was 48.6% and was higher among parents who had vaccinated their children at least once, believed that influenza vaccination protects against severe complications, believed that it is useful, and that it is not better for children to acquire immunization through illness than through vaccination. Conclusions: These findings suggest that efforts should be devoted to educating parents on the risks associated with the disease and the benefits of the vaccine.

Early influenza vaccination rates decline in children during the COVID-19 pandemic

BACKGROUND

This investigation sought to determine whether early season rates of pediatric influenza vaccination changed in a season when there was a concurrent COVID-19 pandemic.

METHODS

This study used cohort and cross sectional data from an academic primary care division in Southcentral Pennsylvania that serves approximately 17,500 patients across 4 practice sites. Early season (prior to November 1) vaccination rates in 2018, 2019 and 2020 were recorded for children, age 6 months to 17 years. To explore the impact of COVID-19 on vaccination, we fit a model with a logit link (estimated via generalized estimating equations to account for clustering by patient over time) on calendar year, adjusted for race, ethnicity, age, and insurance type. We examined interaction effects of demographic covariates with calendar year.

RESULTS

Early vaccination rates were lower in 2020 (29.7%) compared with 2018 and 2019 (34.2% and 33.3%). After adjusting for covariates and accounting for clustering over time, the odds of early vaccination in 2020 were 19% lower compared to 2018 (OR 0.81, 95% CI: 0.78-0.85). In 2020, children with private insurance were more likely to receive early vaccination than in 2018 (OR 1.51, 95% CI: 1.04-1.15), whereas children with public insurance were less likely to receive early vaccination in 2020 than in 2018 (OR 0.62, 95% CI: 1.38-1.65).

CONCLUSIONS

Early influenza vaccination rates declined in a year with a concurrent COVID-19 pandemic. Modeling that accounts for individual trends and demographic variables identified specific populations with lower odds of early vaccination in 2020. Additional research is needed to investigate whether the COVID-19 pandemic impacted parental intent to obtain the influenza vaccine, or introduced barriers to healthcare access.

"Flu-Floppers": Factors Influencing Families' Fickle Flu Vaccination Patterns

While influenza vaccination in the prior year is a strong predictor of subsequent vaccination, many families do not have static vaccination patterns. This study examined factors guiding influenza vaccination decisions among parents whose children sporadically received the influenza vaccination (flu-floppers). We administered surveys to 141 flu-flopper families. Surveys included 21 factors associated with vaccine decision making. A conceptual framework of "passive" and "active" decision making was used to assess parental motivators behind vaccine decisions. The most common reason for vaccinating was a desire to prevent influenza (45%). The most common reason for not vaccinating was a belief that influenza vaccination is not effective (29%). Most parents (88%) reported an active reason in years when their child was vaccinated, while only 43% reported an active reason when their child was not vaccinated (P < .00001). These findings may guide efforts to increase influenza vaccination rates in children most amenable to vaccination.

Disparities in parental awareness of children's seasonal influenza vaccination recommendations and influencers of vaccination

Objective

To determine parental awareness of influenza vaccination recommendations for children and explore associations with awareness.

Design

Cross-sectional survey.

Setting/participants

South Australian parents with a telephone listing in the Electronic White Pages were randomly selected.

Methods

Participants were interviewed using Computer Assisted Telephone Interviewing (CATI) during May–July 2016. Univariable and multivariable analyses explored characteristics associated with awareness; with the survey data weighted to reflect the population of SA and the probability of selection within a household.

Results

Of 539 parents, 33% were aware of the recommendation that all children (<5 years) should receive the influenza vaccine annually with 51.9% aware that children with special risk medical conditions (SRMC) should also receive the vaccine annually. Characteristics strongly associated with parental awareness of the recommendation for children aged < 5 years were knowledge of recommendation for children with a SRMC (adjusted Odds Ratio [aOR] 10.46, CI 4.44–24.63) or living in a metropolitan area (aOR 2.91, CI 1.19–7.09). There was lack of awareness in those not working (aOR 0.13, CI 0.04–0.47), with trade level education (compared with high school) (aOR 0.25 CI, 0.09–0.71) and in those born in the UK or Ireland (aOR 0.19, CI 0.04–0.85). Awareness of the recommendation for children with SRMC to receive the vaccine was strongly associated with knowledge of the influenza recommendation for children <5 years (aOR 10.22, CI 4.39–23.77) or not being born in Australia [UK/ Ireland (aOR 7.63, CI 1.86–31.31); other (aOR 3.93, CI 0.94–16.42)]. The most influential cues to future receipt were a general practitioner (GP) recommendation (63.8%) and providing influenza vaccine free for all children (37.6%). More parents who delayed or excluded vaccines believed that their children’s vaccinations (in general) were unnecessary, as other children were vaccinated (42.8%) compared to those with no or minor concerns (11.1%) (p<0.0001).

Conclusions

Parental awareness of children’s influenza vaccine recommendations is low. Targeted communication strategies and resources are required to establish broader community awareness of recommendations. Healthcare provider endorsement of the vaccine remains key and health care professionals, particularly GPs and paediatric specialists should be encouraged to discuss influenza vaccine with parents at every opportunity. Many parents have vaccine concerns and addressing concerns across the spectrum of hesitancy is crucial.

Influenza vaccine effectiveness against influenza-associated hospitalization in children: A systematic review and meta-analysis

Vaccination remains the most effective way to prevent influenza infection, albeit vaccine effectiveness (VE) varies by year. Compared to other age groups, children and elderly adults have the highest risk of developing influenza-related complications and requiring hospitalization. During the last years, "test negative design" (TND) studies have been implemented in order to estimate influenza VE. The aim of this systematic review and meta-analysis was to summarize the findings of TND studies reporting influenza VE against laboratory-confirmed influenza-related hospitalization in children aged 6 months to 17 years. We searched the PubMed and Embase databases and identified 2615 non-duplicate studies that required detailed review. Among them, 28 met our inclusion criteria and we performed a random-effects meta-analysis using adjusted VE estimates. In our primary analysis, influenza vaccine offered significant protection against any type influenza-related hospitalization (57.48%; 95% CI 49.46-65.49). When we examined influenza VE per type and strain, VE was higher against H1N1 (74.07%; 95% CI: 54.85-93.30) and influenza B (50.87%; 95% CI: 41.75-59.98), and moderate against H3N2 (40.77%; 95% CI: 25.65-55.89). Notably, influenza vaccination offered higher protection in children who were fully vaccinated (61.79%; 95% CI: 54.45-69.13), compared to those who were partially vaccinated (33.91%; 95% CI: 21.12 - 46.69). Also, influenza VE was high in children less than 5 years old (61.71%; 95% CI: 49.29-74.12) as well as in children 6-17 years old (54.37%; 95% CI: 35.14-73.60). In conclusion, in the pediatric population, influenza vaccination offered significant protection against influenza-related hospitalization and complete annual vaccination should be encouraged.

A population-based study of maternal and infant factors influencing influenza vaccination among young children born in Colorado from 2008 to 2016

INTRODUCTION

Influenza causes significant morbidity among young children, and vaccination remains the best strategy to prevent disease. Understanding factors influencing early influenza vaccination uptake are important to identify strategies to increase vaccination rates.

OBJECTIVE

To assess maternal and neonatal factors associated with influenza vaccination among first-born children within the first two years of life.

METHODS

We conducted a retrospective population-based cohort study linking Colorado Birth Registry data and state immunization data of all live births between 2008 and 2016. The cohort was limited to singleton, first births. Multivariable logistic regression was used to assess associations between maternal and neonatal factors and influenza vaccination.

RESULTS

Among 126,763 births meeting criteria for inclusion, 50.2% were vaccinated against influenza by two years of age. Mothers of unvaccinated children were older (27 vs 26 years, p < 0.0001), married (67.8% vs 66.8%, p < 0.0001), with a college education (38.8% vs 37.2%, p < 0.0001). Influenza vaccination rates declined over time by birth year (30.5% in 2009 vs 6.8% in 2013, p < 0.0001). Children admitted to the NICU receiving oxygen with 72 h of birth were 20% less likely to be vaccinated (RR = 0.8, 95% CI: 0.67-0.96) after adjusting for maternal age, race/ethnicity, education and preterm birth. Conversely, premature births were associated with an increase in influenza vaccination by age two years (RR = 1.1, 95%CI: 1.05, 1.15).

CONCLUSIONS

Among a large population-based cohort of mother-infant pairs in Colorado using birth and immunization registry data, there were statistically significant differences in maternal factors between unvaccinated and vaccinated children with influenza in the first 2 years of life, but the differences were too small to be clinically significant. Children admitted to the NICU were 20% less likely to be vaccinated, highlighting the need to target influenza vaccination in this population once eligible. Ongoing studies are needed to explore factors associated with early influenza vaccination.

Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016

BACKGROUND

Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.

OBJECTIVE

This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.

METHODS

Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.

RESULTS

Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.

CONCLUSION

Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.

Complementary and Alternative Medicine and Influenza Vaccine Uptake in US Children

BACKGROUND

Complementary and alternative medicine (CAM) is increasingly used in the United States. Although CAM is mostly used in conjunction with conventional medicine, some CAM practitioners recommend against vaccination, and children who saw naturopathic physicians or chiropractors were less likely to receive vaccines and more likely to get vaccine-preventable diseases. Nothing is known about how child CAM usage affects influenza vaccination.

METHODS

This nationally representative study analyzed ∼9000 children from the Child Complementary and Alternative Medicine File of the 2012 National Health Interview Survey. Adjusting for health services use factors, it examined influenza vaccination odds by ever using major CAM domains: (1) alternative medical systems (AMS; eg, acupuncture); (2) biologically-based therapies, excluding multivitamins/multiminerals (eg, herbal supplements); (3) multivitamins/multiminerals; (4) manipulative and body-based therapies (MBBT; eg, chiropractic manipulation); and (5) mind-body therapies (eg, yoga).

RESULTS

Influenza vaccination uptake was lower among children ever (versus never) using AMS (33% vs 43%; P = .008) or MBBT (35% vs 43%; P = .002) but higher by using multivitamins/multiminerals (45% vs 39%; P < .001). In multivariate analyses, multivitamin/multimineral use lost significance, but children ever (versus never) using any AMS or MBBT had lower uptake (respective odds ratios: 0.61 [95% confidence interval: 0.44-0.85]; and 0.74 [0.58-0.94]).

CONCLUSIONS

Children who have ever used certain CAM domains that may require contact with vaccine-hesitant CAM practitioners are vulnerable to lower annual uptake of influenza vaccination. Opportunity exists for US public health, policy, and medical professionals to improve child health by better engaging parents of children using particular domains of CAM and CAM practitioners advising them.

Increasing childhood influenza vaccination: a cluster randomized trial

BACKGROUND

Since the 2008 inception of universal childhood influenza vaccination, national rates have risen more dramatically among younger children than older children and reported rates across racial/ethnic groups are inconsistent. Interventions may be needed to address age and racial disparities to achieve the recommended childhood influenza vaccination target of 70%.

PURPOSE

To evaluate an intervention to increase childhood influenza vaccination across age and racial groups.

METHODS

In 2011-2012, a total of 20 primary care practices treating children were randomly assigned to the intervention and control arms of a cluster randomized controlled trial to increase childhood influenza vaccination uptake using a toolkit and other strategies including early delivery of donated vaccine, in-service staff meetings, and publicity.

RESULTS

The average vaccination differences from pre-intervention to the intervention year were significantly larger in the intervention arm (n=10 practices) than the control arm (n=10 practices); for children aged 9-18 years (11.1 pct pts intervention vs 4.3 pct pts control, p<0.05); for non-white children (16.7 pct pts intervention vs 4.6 pct pts control, p<0.001); and overall (9.9 pct pts intervention vs 4.2 pct pts control, p<0.01). In multi-level modeling that accounted for person- and practice-level variables and the interactions among age, race, and intervention, the likelihood of vaccination increased with younger age group (6-23 months); white race; commercial insurance; the practice's pre-intervention vaccination rate; and being in the intervention arm. Estimates of the interaction terms indicated that the intervention increased the likelihood of vaccination for non-white children in all age groups and white children aged 9-18 years.

CONCLUSIONS

A multi-strategy intervention that includes a practice improvement toolkit can significantly improve influenza vaccination uptake across age and racial groups without targeting specific groups, especially in practices with large percentages of minority children.

Influenza vaccination of Michigan children by provider type, 2010-2011

BACKGROUND

Influenza vaccination for all children aged 6 months to 18 years has been recommended since 2008 to prevent flu-related morbidity and mortality. However, 2010-2011 influenza vaccine coverage estimates show under-vaccination in children of all ages. We examined predictors of influenza vaccination in Michigan during the 2010-2011 influenza season.

PURPOSE

To determine whether immunization provider type was associated with a child's influenza vaccination in Michigan and assess whether county-level factors were confounders of the association.

METHODS

Influenza vaccinations reported to the Michigan Care Improvement Registry from the 2010-2011 influenza season were analyzed in 2012 to estimate ORs for the association between immunization provider type and influenza vaccination.

RESULTS

Among 2,373,826 Michigan children aged 6 months through 17 years, 17% were vaccinated against influenza and lower vaccination rates were observed for public compared to private providers (13% vs 18%). In the unadjusted model, public providers had lower odds of vaccinating children compared to private providers (OR=0.60, 95% CI=0.60, 0.61). County-level factors, including percentage of families living below the poverty line, median household income, and percentage black race, were not shown to confound the association. In the adjusted models, public providers had lower odds of vaccinating children compared to private providers (OR=0.87, 95% CI=0.86, 0.88).

CONCLUSIONS

Although a child's likelihood of influenza vaccination in Michigan varies by provider type, more effective strategies to improve influenza vaccination rates for all Michigan children are needed.

Cluster randomized trial of a toolkit and early vaccine delivery to improve childhood influenza vaccination rates in primary care

PURPOSE

To increase childhood influenza vaccination rates using a toolkit and early vaccine delivery in a randomized cluster trial.

METHODS

Twenty primary care practices treating children (range for n=536-8183) were randomly assigned to Intervention and Control arms to test the effectiveness of an evidence-based practice improvement toolkit (4 Pillars Toolkit) and early vaccine supplies for use among disadvantaged children on influenza vaccination rates among children 6 months-18 years. Follow-up staff meetings and surveys were used to assess use and acceptability of the intervention strategies in the Intervention arm. Rates for the 2010-2011 and 2011-2012 influenza seasons were compared. Two-level generalized linear mixed modeling was used to evaluate outcomes.

RESULTS

Overall increases in influenza vaccination rates were significantly greater in the Intervention arm (7.9 percentage points) compared with the Control arm (4.4 percentage points; P<0.034). These rate changes represent 4522 additional doses in the Intervention arm vs. 1390 additional doses in the Control arm. This effect of the intervention was observed despite the fact that rates increased significantly in both arms - 8/10 Intervention (all P<0.001) and 7/10 Control sites (P-values=0.04 to <0.001). Rates in two Intervention sites with pre-intervention vaccination rates >58% did not significantly increase. In regression analyses, a child's likelihood of being vaccinated was significantly higher with: younger age, white race (Odds ratio [OR]=1.29; 95% confidence interval [CI]=1.23-1.34), having commercial insurance (OR=1.30; 95%CI=1.25-1.35), higher pre-intervention practice vaccination rate (OR=1.25; 95%CI=1.16-1.34), and being in the Intervention arm (OR=1.23; 95%CI=1.01-1.50). Early delivery of influenza vaccine was rated by Intervention practices as an effective strategy for raising rates.

CONCLUSIONS

Implementation of a multi-strategy toolkit and early vaccine supplies can significantly improve influenza vaccination rates among children in primary care practices but the effect may be less pronounced in practices with moderate to high existing vaccination rates. Clinical trial registry name/number: From Innovation to Solutions: Childhood Influenza/NCT01664793.

Seasonal influenza vaccination at school: a randomized controlled trial

BACKGROUND

Influenza vaccination coverage for U.S. school-aged children is below the 80% national goal. Primary care practices may not have the capacity to vaccinate all children during influenza vaccination season. No real-world models of school-located seasonal influenza (SLV-I) programs have been tested.

PURPOSE

Determine the feasibility, sustainability, and impact of an SLV-I program providing influenza vaccination to elementary school children during the school day.

DESIGN

In this pragmatic randomized controlled trial of SLV-I during two vaccination seasons, schools were randomly assigned to SLV-I versus standard of care. Seasonal influenza vaccine receipt, as recorded in the state immunization information system (IIS), was measured.

SETTING/PARTICIPANTS

Intervention and control schools were located in a single western New York county. Participation (intervention or control) included the sole urban school district and suburban districts (five in Year 1, four in Year 2).

INTERVENTION

After gathering parental consent and insurance information, live attenuated and inactivated seasonal influenza vaccines were offered in elementary schools during the school day.

MAIN OUTCOME MEASURES

Data on receipt of ≥1 seasonal influenza vaccination in Year 1 (2009-2010) and Year 2 (2010-2011) were collected on all student grades K through 5 at intervention and control schools from the IIS in the Spring of 2010 and 2011, respectively. Additionally, coverage achieved through SLV-I was compared to coverage of children vaccinated elsewhere. Preliminary data analysis for Year 1 occurred in Spring 2010; final quantitative analysis for both years was completed in late Fall 2012.

RESULTS

Results are shown for 2009-2010 and 2010-2011, respectively: Children enrolled in suburban SLV-I versus control schools had vaccination coverage of 47% vs 36%, and 52% vs 36% (p<0.0001 both years). In urban areas, coverage was 36% vs 26%, and 31% vs 25% (p<0.001 both years). On multilevel logistic analysis with three nested levels (student, school, school district) during both vaccination seasons, children were more likely to be vaccinated in SLV-I versus control schools; ORs were 1.6 (95% CI=1.4, 1.9; p<0.001) and 1.5 (95% CI=1.3, 1.8; p<0.001).

CONCLUSIONS

Delivering influenza vaccine during school is a promising approach to improving pediatric influenza vaccination coverage.

TRIAL REGISTRY

ClinicalTrials.govNCT01224301.

Factors associated with in-office influenza vaccination by U.S. pediatric providers

BACKGROUND

In the United States, influenza vaccination is recommended for all children 6 months and older; however, vaccination rates are below target levels. A broad sample of U.S. pediatric offices was assessed to determine factors that influence in-office influenza vaccination rates.

METHODS

Offices (N = 174) were recruited to participate in an observational study over three influenza seasons (2008-2009, 2009-2010, 2010-2011). Only data from the first year of an office's participation in the study were used. Associations of coverage and 2-dose compliance rates with office characteristics and selected vaccination activities were examined using univariate regression analyses and linear regression analyses using office characteristics identified a priori and vaccination activities with P values ≤ 0.10 in univariate analyses.

RESULTS

Influenza vaccination coverage for children 6 months to 18 years of age averaged 25.2% (range: 2.0%-69.1%) and 2-dose compliance for children < 9 years of age averaged 53.4% (range: 5.4%-96.2%). Factors associated with increased coverage were non-rural site (P = 0.025), smaller office size (fewer than 5000 patients; P < 0.001), use of evening and weekend hours to offer influenza vaccine (P = 0.004), a longer vaccination period (P = 0.014), and a greater influenza vaccine coverage rate among office staff (P = 0.012). Increased 2-dose compliance was associated with smaller office size (P = 0.001) and using patient reminders (P = 0.012) and negatively related to use of electronic provider reminders to vaccinate (P = 0.003).

CONCLUSIONS

To maximize influenza vaccine coverage and compliance, offices could offer the vaccine during evening and weekend hours, extend the duration of vaccine availability, encourage staff vaccination, and remind patients that influenza vaccination is due. Additional efforts may be required in large offices and those in rural locations.

Low rates of influenza immunization in young children under Ontario's universal influenza immunization program

OBJECTIVES

To determine physician-administered influenza vaccine coverage for children aged 6 to 23 months in a jurisdiction with a universal influenza immunization program during 2002-2009 and to describe predictors of vaccination.

METHODS

By using hospital records, we identified all infants born alive in Ontario hospitals from April 2002 through March 2008. Immunization status was ascertained by linkage to physician billing data. Children were categorized as fully, partially, or not immunized depending on the number and timing of vaccines administered. Generalized linear mixed models determined the association between immunization status and infant, physician, and maternal characteristics.

RESULTS

Influenza immunization was low for the first influenza season of the study period (1% fully immunized during the 2002-2003 season), increased for the following 3 seasons (7% to 9%), but then declined (4% to 6% fully immunized during the 2006-2007 to 2008-2009 seasons). Children with chronic conditions or low birth weight were more likely to be immunized. Maternal influenza immunization (adjusted odds ratio 4.31; 95% confidence interval 4.21-4.40), having a pediatrician as the primary care practitioner (adjusted odds ratio 1.85; 95% confidence interval 1.68-2.04), high visit rates, and better continuity of care were all significantly associated with full immunization, whereas measures of social disadvantage were associated with nonimmunization. Low birth weight infants discharged from neonatal care in the winter were more likely to be immunized.

CONCLUSIONS

Influenza vaccine coverage among children aged 6 to 23 months in Ontario is low, despite a universal vaccination program and high primary care visit rates. Interventions to improve coverage should target both physicians and families.

In-office influenza vaccination by US pediatric providers varies greatly and is higher among smaller offices

During the 2010-2011 US influenza season, 105 pediatric and 13 family practice offices participated in a prospective observational study of in-office influenza vaccination of children. Office characteristics, influenza vaccinations, and vaccination-related activities were reported. Among pediatric offices, first dose vaccination rates (2% to 60%), 2-dose compliance (11% to 100%), the duration of vaccine availability (60-302 days), and office visit type (well vs sick vs clinic) used for vaccinations varied greatly. Pediatric offices had higher vaccination coverage than family practice offices, offered vaccine longer, and administered more vaccinations during sick visits. Smaller offices and higher staff vaccination rates were associated with higher vaccination coverage. Smaller offices and video reminders in waiting rooms were associated with enhanced 2-dose compliance among children younger than 9 years. A greater understanding of interoffice variability in influenza vaccine delivery by US pediatric providers should allow for the creation of more effective strategies to improve pediatric influenza vaccination rates.

The ins and outs of universal childhood influenza vaccination

Influenza viruses continue to cause disease of varying severity among humans. People with underlying disease and the elderly are at increased risk of developing severe disease after infection with an influenza virus. As effective and safe vaccines are available, the WHO has recommended vaccinating these groups against influenza annually. In addition to this recommendation, public health authorities of a number of countries have recently recommended vaccinating all healthy children aged 6-59 months against influenza. Here, we review the currently available data concerning the burden of disease in children, the economical impact of implementing universal vaccination of children, the efficacy of currently available influenza virus vaccines, the theoretical concerns regarding preventing immunity otherwise induced by infections with seasonal influenza viruses, and finally, how to address these concerns.

The impact of missed opportunities on seasonal influenza vaccination coverage for healthy young children

OBJECTIVE

To estimate the impact of missed opportunities on influenza vaccination coverage among 6- through 23-month-old children who sought medical care during the 2004-2005 influenza season.

DESIGN

Retrospective cohort study.

SETTING

Fifty-two primary care practice sites located in Rochester, New York, Nashville, Tennessee, and Cincinnati, Ohio.

PARTICIPANTS

Children 6 through 23 months of age. METHODS/OUTCOME MEASURE: Charts were reviewed and data collected on influenza vaccinations, type of health care visit (well child or other), and presence of illness symptoms. Missed opportunity was defined as a practice visit by an eligible child during influenza season, when vaccine was available, but during which the child did not receive an influenza vaccination. Vaccine was assumed to be available between the first and last dates influenza vaccination was recorded at that practice. Each child was classified as fully vaccinated, partially vaccinated, or unvaccinated.

RESULTS

Data were analyzed for 1724 children, 6 through 23 months of age. Most children (62.0%) had at least 1 missed opportunity during this period. Among children with any missed opportunities, 12.8% were fully and 29.8% were partially vaccinated. Overall, 33.6% of the missed opportunities occurred during well child visits and 66.4% during other types of visits; 75% occurred when no other vaccines were given. Eliminating all missed opportunities would have increased full vaccination coverage from 30.3% to 49.9%.

CONCLUSIONS

Missed opportunities for influenza vaccination are frequent. Reducing missed opportunities could significantly increase influenza vaccination rates and should be a goal in each practice.

Assessment of parental report for 2009-2010 seasonal and monovalent H1N1 influenza vaccines among children in the emergency department or hospital

OBJECTIVE

To assess the validity of parental report for seasonal and monovalent H1N1 influenza vaccinations among children 6 months to <18 years who were recommended to receive both vaccines in 2009-2010.

METHODS

Children with fever or respiratory symptoms were prospectively enrolled in both emergency departments in Forsyth County, North Carolina, and the only pediatric hospital in the region. Enrollment occurred from September 1, 2009, through April 12, 2010, during the H1N1 influenza pandemic. A parental questionnaire was administered by trained interviewers to ascertain the status of seasonal and monovalent H1N1 influenza vaccines. Parental report was compared with that documented in the medical record and/or the North Carolina immunization registry.

RESULTS

Among 297 enrolled children 6 months to <18 years of age, 174 (59%) were 6 months to 4 years, 67 (23%) were 5-8 years, and 56 (19%) were 9 to <18 years. Parents reported that 140 (47%) children had received ≥1 dose of 2009-2010 influenza vaccine-128 (43%) for seasonal vaccine and 63 (21%) for H1N1 vaccine. Confirmed vaccination data indicated that 156 (53%) children had received ≥1 dose of any 2009-2010 vaccine-120 (40%) for seasonal vaccine and 53 (18%) for H1N1 vaccine. Parental report of any seasonal influenza vaccination was 92% sensitive and 86% specific and had a kappa of 0.76. Parental report for any H1N1 influenza vaccination was 88% sensitive and 92% specific with a kappa of 0.71.

CONCLUSIONS

Parental report of 2009-2010 seasonal and monovalent H1N1 influenza vaccinations was sensitive and specific and had reasonable agreement with the medical record and/or immunization registry.