Improving Influenza Vaccination in Children With Comorbidities: A Systematic Review

Parent and family characteristics associated with reported pediatric influenza vaccination in a sample of Canadian digital vaccination platform users. An exploratory, cross-sectional study in the 2018-2019 influenza season

Seasonal vaccination remains one of the best interventions to prevent morbidity and mortality from influenza in children. Understanding the characteristics of parents who vaccinate their children can inform communication strategies to encourage immunization. Using a cross-sectional study, we described parental characteristics of people who reported vaccinating their children against influenza during 2018/2019 in a cohort of Canadian digital immunization record users. Data was collected from a free, Pan-Canadian digital vaccination tool, CANImmunize. Eligible accounts contained at least one parental and one "child/dependent" record. Each parental characteristic (gender, age, family size, etc) was tested for association with pediatric influenza vaccination, and a multivariate logistic regression model was fit. A total of 6,801 CANImmunize accounts met inclusion criteria. After collapsing the dataset, the final sample contained 11,381 unique dyads. Influenza vaccination was reported for 32.3% of the children and 42.0% of the parents. In the multivariate logistic regression analysis, parents receiving the seasonal influenza vaccine were most strongly associated with reporting pediatric influenza vaccination (OR 17.05, 95% CI 15.08, 19.28). Having a larger family size and fewer transactions during the study period was associated with not reporting pediatric influenza vaccination. While there are several limitations to this large-scale study, these results can help inform future research in the area. Digital technologies may provide a unique and valuable source of vaccine coverage data and to explore associations between individual characteristics and immunization behavior. Policy makers considering digital messaging may want to tailor their efforts based on parental characteristics to further improve pediatric seasonal influenza vaccine uptake.

Health Insurance Type and Outpatient Specialist Care Among Children With Asthma

Importance

Although children with asthma are often successfully treated by primary care clinicians, outpatient specialist care is recommended for those with poorly controlled disease. Little is known about differences in specialist use for asthma among children with Medicaid vs private insurance.

Objective

To examine differences among children with asthma regarding receipt of asthma specialist care by insurance type.

Design, Setting, and Participants

In this cross-sectional study using data from the Massachusetts All Payer Claims Database (APCD) between 2014 to 2020, children with asthma were identified and differences in receipt of outpatient specialist care by whether their insurance was public (Medicaid and the Children's Health Insurance Program) or private were examined. Eligible participants included children with asthma in 2015 to 2020 aged 2 to 17 years. Data analysis was conducted from January 2023 to April 2024.

Exposure

Medicaid vs private insurance.

Main Outcomes and Measures

The primary outcome was receipt of specialist care (any outpatient visit with a pulmonology, allergy and immunology, or otolaryngology physician). Multivariable logistic regression models estimated differences in receipt of specialist care by insurance type accounting for child and area characteristics including demographics, health status, persistent asthma, calendar year, and zip code characteristics. Additional analyses examined if the associations of specialist care with insurance type varied by asthma persistence and severity, and whether associations varied over time.

Results

Among 198 101 unique children, there were 432 455 child-year observations (186 296 female [43.1%] and 246 159 male [56.9%]; 211 269 aged 5 to 11 years [48.9%]; 82 108 [19.0%] with persistent asthma) including 286 408 (66.2%) that were Medicaid insured and 146 047 (33.8%) that were privately insured. Although persistent asthma was more common among child-year observations with Medicaid vs private insurance (57 381 [20.0%] vs 24 727 [16.9%]), children with Medicaid were less likely to receive specialist care. Overall, 64 239 child-year observations (14.9%) received specialist care, with substantially lower rates for children with Medicaid vs private insurance (34 093 child-year observations [11.9%] vs 30 146 child-year observations [20.6%]). Regression-based estimates confirmed these disparities; children with Medicaid had 55% lower odds of receiving specialist care (adjusted odds ratio, 0.45; 95% CI, 0.43 to 0.47) and a regression-adjusted 9.7 percentage point (95% CI, -10.4 percentage points to -9.1 percentage points) lower rate of receipt of specialist care. Compared with children with private insurance, there was an additional 3.2 percentage point (95% CI, 2.0 percentage points to 4.4 percentage points) deficit for children with Medicaid with persistent asthma.

Conclusions and Relevance

In this cross-sectional study, children with Medicaid were less likely to receive specialist care, with the largest gaps among those with persistent asthma. These findings suggest that closing this care gap may be one approach to addressing ongoing disparities in asthma outcomes.

Differences in Health Care Utilization for Asthma by Children with Medicaid versus Private Insurance

Asthma is the most common chronic disease in children, disproportionately affects families with lower incomes, and is a leading reason for acute care visits and hospitalizations. This retrospective cohort study used the Massachusetts All Payer Claims Database (2014-2018) to examine differences in acute care utilization and quality of care for asthma between Medicaid- and privately insured children in Massachusetts. Outcomes included acute care use (emergency department [ED] or hospitalization), ED visits with asthma, routine asthma visits, and filled prescriptions for asthma medications. Multivariable logistic regression was used to account for differences in demographics, ZIP codes, health status, and asthma severity. Overall, 10.0% of Medicaid-insured children and 5.6% of privately insured were classified as having asthma. Among 317,596 child-year observations for children with asthma, 64.4% were insured by Medicaid. Medicaid-insured children had higher rates of any acute care use (50.4% vs. 30.0%) and ED visits with an asthma diagnosis (27.2% vs. 13.3%) compared to privately insured children. Only 65.4% of Medicaid enrollees had at least one routine asthma visit compared to 74.3% of privately insured children. Most children received at least one asthma medication (88.6% Medicaid vs. 83.3% privately insured), but a higher percentage of Medicaid-insured children received at least one rescue medication (84.0% vs. 73.7%), and a lower percentage of Medicaid-insured (46.1% vs. 49.2%) received a controller medication. These results suggest that opportunities for improvement in childhood asthma persist, particularly for children insured by Medicaid.

Herpes Zoster Vaccine Uptake and Active Campaign Impact, a Multicenter Retrospective Study in Italy

The Herpes Zoster (HZ) vaccination has proven both safe and effective in alleviating conditions related to HZ, leading to significant cost savings in national healthcare and social systems. In Italy, it is recommended and provided free of charge to individuals aged 65 and older. To achieve broad vaccination coverage, alongside ordinary immunization campaigns, active and catch-up campaigns were implemented. This retrospective observational study aimed to observe the vaccination coverage achieved in the Romagna Local Health Authority (LHA) during the 2023 active campaign, with a secondary goal of assessing the impact of the 2022 catch-up campaign and the 2023 active campaign compared to ordinary campaigns. As of 3 July 2023, an overall vaccine uptake of 13.5% was achieved among individuals born in 1958, with variations among the four LHA centers ranging from 10.2% to 17.7%. Catch-up and active campaigns together contributed to nearly half of the achieved coverage in Center No. 1 and a quarter in Center No. 2. Notably, individuals born in 1957, not included in the Center No. 2 catch-up campaign, reached significantly lower vaccination coverage compared to other cohorts and centers. Analyzing the use of text messages for active campaigns, it was observed that cohort groups did not show substantial differences in text-message utilization for warnings. However, having relatives who had experienced HZ-related symptoms significantly reduced the reliance on text messages as warnings. These results highlighted how catch-up and active campaigns effectively increased vaccine coverage. Nevertheless, differences in uptake among different centers within the same LHA and the limited contribution of other information sources compared to text messages suggest the necessity of designing campaigns involving all available channels and stakeholders to maximize vaccine uptake.

Influenza Vaccinations Among Privately and Publicly Insured Children With Asthma

OBJECTIVE

Annual influenza vaccination rates for children remain well below the Healthy People 2030 target of 70%. We aimed to compare influenza vaccination rates for children with asthma by insurance type and to identify associated factors.

METHODS

This cross-sectional study examined influenza vaccination rates for children with asthma by insurance type, age, year, and disease status using the Massachusetts All Payer Claims Database (2014-2018). We used multivariable logistic regression to estimate the probability of vaccination accounting for child and insurance characteristics.

RESULTS

The sample included 317,596 child-year observations for children with asthma in 2015-18. Fewer than half of children with asthma received influenza vaccinations; 51.3% among privately insured and 45.1% among Medicaid insured. Risk modeling reduced, but did not eliminate, this gap; privately insured children were 3.7 percentage points (pp) more likely to receive an influenza vaccination than Medicaid-insured children (95% confidence interval [CI]: 2.9-4.5pp). Risk modeling also found persistent asthma was associated with more vaccinations (6.7pp higher; 95% CI: 6.2-7.2pp), as was younger age. The regression-adjusted probability of influenza vaccination in a non-office setting was 3.2pp higher in 2018 than 2015 (95% CI: 2.2-4.2pp), and significantly lower for children with Medicaid.

CONCLUSIONS

Despite clear recommendations for annual influenza vaccinations for children with asthma, low rates persist, particularly for children with Medicaid. Offering vaccines in non-office settings such as retail pharmacies may reduce barriers, but we did not observe increased vaccination rates in the first years after this policy change.

Parental Acceptance, Parental Hesitancy, and Uptake of Seasonal Influenza Vaccination among Children Aged 6-59 Months: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis summarises the literature on parental acceptance, parental hesitancy, uptake, and the associated factors of seasonal influenza vaccination (SIV) among children aged 6-59 months. Studies were sourced from the following platforms: PubMed, Web of Science, MEDLINE, and EMBASE databases. A random-effects model was used to evaluate the prevalence and 95% confidence intervals (CI) of parental acceptance, parental hesitancy, and SIV uptake in the last flu season and lifetime among children. A total of 36 studies were included for analysis. The overall prevalence was 64% for parental acceptance (95% CI: 51-75%), 34% for parental hesitancy (95% CI: 22-48%), 41% for SIV uptake in the last flu season (95% CI: 33-50%), and 46% for SIV uptake in a lifetime (95% CI: 20-74%). Associated factors of parental acceptance/hesitancy and uptake included the age of the children or parents, parental education level, household income level, ethnicity, and other modifiable factors, including perceived benefits, perceived barriers, perceived severity, perceived susceptibility, and cues to action related to SIV. Meta-regression analyses revealed regional differences in parental acceptance (Americas: 79% vs. Asia: 60%). The results provided implications informing us of the development of intervention programs targeting parents to improve SIV coverage among young children.

Short Message Service Reminder Nudge for Parents and Influenza Vaccination Uptake in Children and Adolescents With Special Risk Medical Conditions: The Flutext-4U Randomized Clinical Trial

Importance

Children with chronic medical conditions are at increased risk of severe influenza. Uptake of influenza vaccination in children and adolescents with these identified special risk medical conditions (SRMCs) is suboptimal.

Objective

To assess the effectiveness of Flutext-4U, a parent short message service (SMS) reminder nudge intervention, in increasing influenza immunization in children and adolescents with SRMCs.

Design, Setting, and Participants

This randomized clinical trial was conducted at a tertiary pediatric hospital in Adelaide, South Australia, from April 15 to September 30, 2021. Children and adolescents aged 6 months to younger than 18 years with SRMCs and a subspecialist outpatient appointment over a 5-month period during the Australian seasonal influenza vaccination season (April-August 2021) were eligible to participate. Follow-up was until September 30, 2021.

Interventions

Participants were randomly assigned (1:1 ratio) to control: clinician nudges (hospital vaccine availability, ease of access, and recommendation from hospital subspecialists) or SMS intervention (control conditions plus an additional SMS reminder nudge to parents), with randomization stratified by age group (<5 years, 5-14 years, or >14 to <18 years).

Main Outcomes and Measures

The primary outcome was influenza vaccination, as confirmed by the Australian Immunisation Register.

Results

A total of 600 participants (intervention group: 298 [49.7%]; mean [SD] age, 11.5 [4.6] years; 162 female participants [54.4%]; control group: 302 [50.3%]; mean [SD] age, 11.4 [4.7] years; 155 female participants [51.3%]) were included. Influenza vaccination was 38.6% (113 of 293) in the SMS intervention group compared with 26.2% (79 of 302) in the control group (adjusted odds ratio [aOR], 1.79; 95% CI, 1.27-2.55; P = .001). Time to vaccine receipt was significantly lower among SMS participants (adjusted hazard ratio, 1.67; 95% CI, 1.25-2.22; P < .001). For participants randomly assigned by June 15, a significantly greater proportion receiving the SMS intervention were vaccinated during the optimal delivery period April to June 30 (SMS group: 40.0% [76 of 190] vs 25.4% [50 of 197]; aOR, 1.97; 95% CI, 1.28-3.06; P = .002).

Conclusions and Relevance

Results of this randomized clinical trial suggest that an additional SMS reminder nudge for parents delivered in the tertiary care hospital setting to children and adolescents with SMRCs resulted in higher influenza vaccine uptake compared with clinician nudges alone.

Trial Registration

ANZCTR Identifier: ACTRN12621000463875.

Determinants of parental seasonal influenza vaccine hesitancy in the Eastern Mediterranean region: A cross-sectional study

Background

Seasonal influenza vaccine can reduce the risk of influenza-associated hospitalizations and deaths among children. Given that parents are the primary decision makers, this study examined the parental attitude toward childhood influenza vaccine and identified determinants of vaccine hesitancy (VH) in the Eastern Mediterranean region (EMR).

Methods

A cross-sectional study was conducted using an anonymous online survey in 14 EMR countries. Parents of children aged 6 months to 18 years were included. The Parent Attitude about Childhood Vaccines (PACV) was used to assess VH. Chi square test and independent t-test were used to test for association of qualitative and quantitative variables, respectively. A structural equations model (SEM) was used to identify direct and indirect determinants of parental VH.

Results

Almost half of the parents were hesitant about vaccinating their children against influenza (50.8%). Parental VH was significantly higher among older mothers (37.06 ± 8.8 years, p = 0.006), rural residents (53.6%, p &lt; 0.001), high-income countries residents (50.6%, p &lt; 0.001), and mothers with higher educational levels (52.1%, p &lt; 0.001). Parents of school-aged children (5–9 years) (55.6%, p &lt; 0.001), children free from any comorbidities (52.5%, p &lt; 0.001), children who did not receive routine vaccination at all (51.5%, p = 0.03), children who were not vaccinated against COVID-19 (54.3%, p &lt; 0.001), in addition to parents who were not vaccinated against influenza (57.1%, p &lt; 0.001) were significantly associated with increased likelihood of VH. Parents who were depending on healthcare provider as a source of information regarding vaccines were less likely to report VH (47.9%, p &lt; 0.001), meanwhile those who used social media as their source of health information showed a significantly higher VH (57.2%, p &lt; 0.001). The SEM suggested that mother’s age, residence, country income level, child gender, total number of children and source of information regarding vaccines had a direct effect on VH. Meanwhile, parents vaccinated against influenza, children completely or partially vaccinated with routine vaccines and children vaccinated against Coronavirus disease 2019 (COVID-19) had an indirect effect on VH.

Conclusion

A high proportion of included parents were hesitant to vaccinate their children against seasonal influenza. This attitude is due to many modifiable and non-modifiable factors that can be targeted to improve vaccination coverage.

VACS: VAccination disComfort Scale

The vaccination of children is a crucial tool to protect both individuals and the world in general from various diseases and pathogens. Unfortunately, the vaccination procedure is not a pleasant one for all children, with many experiencing various levels of discomfort, sometimes reaching intolerable levels. In the first part of this work, we develop VACS, a tool that measures the discomfort children experience during vaccination. VACS takes into consideration the complete timeline of the vaccination experience from the perspective of the child, starting from the moment the child enters the doctor's office through to their departure, and also the complete range of manifestations of discomfort, ranging from moaning and crying to facial expressions and posture. Their discomfort is quantified as a number from 0 to 25, with zero corresponding to a smooth vaccination and 25 to maximal/unbearable discomfort. In the second part of the work, we apply VACS to 40 vaccinations of children aged 2 to 12. Our findings show that approximately 40% of the children do not face discomfort during vaccination, but for the rest discomfort of varying degrees is observed. We also find that doctors are content with their patients facing considerably higher discomfort levels than what the children themselves are willing to withstand: doctors are content with VACS values up to 19 whilst children start to suffer when the VACS value exceeds 11. Surprisingly, characteristics such as (a) gender, (b) whether the state's recommended vaccination program has been implemented in full, and even (c) prior negative vaccination experiences are found to be poor predictors of vaccination discomfort. Age on the other hand may be a factor, with younger children experiencing discomfort more often and more intensely; more research is required in order to validate this with higher confidence. The formulation of VACS opens the door for more systematic work towards the mitigation of vaccination discomfort for children.

Australian hospital paediatricians and nurses' perspectives and practices for influenza vaccine delivery in children with medical comorbidities

INTRODUCTION

Influenza vaccination of children with medical comorbidities is critical due their increased risks for severe influenza disease. In Australia, hospitals are an avenue for influenza vaccine delivery to children with comorbidities but are not always effectively utilised. Qualitative enquiry sought to ascertainment the barriers and enablers for influenza vaccination recommendation, delivery, and recording of these children at Australian hospitals.

METHODS

Semi-structured interviews and discussion group sessions were conducted with paediatricians and nurses at four tertiary paediatric specialist hospitals and two general community hospitals in three Australian states. Transcripts from interviews and group sessions were inductively analysed for themes. The Capability, Opportunity, Motivation, and Behaviour (COM-B) model was used to explore the elements of each theme and identify potential interventions to increase influenza vaccination recommendation and delivery behaviours by providers.

RESULTS

Fifteen discussion sessions with 28 paediatricians and 26 nurses, and nine in-depth interviews (five paediatricians and four nurses) were conducted. Two central thematic domains were identified: 1. The interaction between hospital staff and parents/patients for influenza vaccine recommendation, and 2. Vaccination delivery and recording in the hospital environment. Six themes across these domains emerged detailing the importance of dedicated immunisation services, hospital leadership, paediatricians' vaccine recommendation role, the impact of comorbidities, vaccination recording, and cocooning vaccinations. Supportive hospital leadership, engaged providers, and dedicated immunisation services were identified as essential for influenza vaccination of children with comorbidities in Australian hospital.

CONCLUSION

Recommendation of influenza vaccination for Australian children with comorbidities is impacted by the beliefs of paediatricians and the perceived impact of influenza disease on children's comorbidities. Dedicated immunisation services and supportive hospital leadership were drivers for influenza vaccine delivery at hospitals. Future interventions targeting hospital-based influenza vaccine delivery for children with comorbidities should take a rounded approach targeting providers' attitudes, the hospital environment and leadership support.

Influenza vaccination among caregivers and household contacts of children with congenital heart disease before and during COVID-19 pandemic

AIM

We aimed to investigate the influenza immunisation status of caregivers and household contacts of children with congenital heart disease (CHD) and potential barriers to vaccine uptake.

METHODS

Prospective questionnaire-based survey over two influenza seasons (2019-2020 and 2020-2021) on 161 children with CHD attending a tertiary paediatric cardiology clinic and their families. Logistic regression and factor analysis were performed to identify factors associated with influenza vaccine uptake.

RESULTS

Influenza vaccination coverage of children was 65%, whereas that of their fathers and mothers was 34% and 26%, respectively. Children with unvaccinated siblings represented 43% and those with unvaccinated adults in the household 79% of our study population. No statistically significant differences were found before and during COVID-19 pandemic on vaccine uptake. Logistic regression analysis showed that higher education level, understanding the risk of contracting the disease and vaccination status of the child determined the vaccination status of parents, regardless of their age, age of their child, severity of CHD, beliefs about vaccine safety and efficacy and risk of transmission if not vaccinated. Factor analysis revealed distinct groups among unvaccinated parents (76.3% of the variation in the responses).

CONCLUSIONS

Vaccination coverage of caregivers and household contacts of children with CHD is suboptimal. Influenza vaccination campaigns should take into consideration the specific characteristics of parental groups and target interventions accordingly to increase their vaccine uptake and indirectly protect children with CHD.

Using provider-parent strategies to improve influenza vaccination in children and adolescents with special risk medical conditions: a randomised controlled trial protocol

INTRODUCTION

Influenza immunisation is a highly cost-effective public health intervention. Despite a comprehensive National Immunisation Program, influenza vaccination in children and adolescents with special risk medical conditions (SRMCs) is suboptimal. Flutext-4U is an innovative, multi-component strategy targeting paediatric hospitals, general practice and parents of children and adolescents with SRMC. The Flutext-4U study aims to assess the impact of Flutext-4U to increase influenza immunisation in children and adolescents with SRMC.

METHODS AND ANALYSIS

This is a randomised controlled trial involving parents of children and adolescents (aged >6 months to <18 years) with SRMC receiving tertiary care at the Women's and Children's Hospital (WCH), Adelaide, South Australia, who are eligible for funded influenza immunisation with a hospital appointment between the start of the seasonal influenza vaccination season and 31 July 2021, their treating general practitioners (GPs), and WCH paediatric specialists.Parents (of children/adolescents with SRMC) are randomised (1:1 ratio) to standard care plus intervention (SMS reminder messages to parents; reminders (written correspondence) for their child's GP from the hospital's Paediatric Outpatients Department) or standard care (hospital vaccine availability, ease of access and reminders for WCH subspecialists) with randomisation stratified by age-group (<5, 5-14, >14 to <18 years).The primary outcome is influenza vaccination, as confirmed by the Australian Immunisation Register.The proportion vaccinated (primary outcome) will be compared between randomised groups using logistic regression, with adjustment made for age group at randomisation. The effect of treatment will be described using an OR with a 95% CI.

ETHICS AND DISSEMINATION

The protocol and all study materials have been reviewed and approved by the Women's and Children's Health Network Human Research Ethics Committee (HREC/20/WCHN/5). Results will be disseminated via peer-reviewed publication and at scientific meetings, professional and public forums.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12621000463875).

Influenza hospitalizations in Australian children 2010-2019: The impact of medical comorbidities on outcomes, vaccine coverage, and effectiveness

BACKGROUND

Children with comorbidities are at greater risk of severe influenza outcomes compared with healthy children. In Australia, influenza vaccination was funded for those with comorbidities from 2010 and all children aged <5 years from 2018. Influenza vaccine coverage remains inadequate in children with and without comorbidities.

METHODS

Children ≤16 years admitted with acute respiratory illness and tested for influenza at sentinel hospitals were evaluated (2010-2019). Multivariable regression was used to identify predictors of severe outcomes. Vaccine effectiveness was estimated using the modified incidence density test-negative design.

RESULTS

Overall, 6057 influenza-confirmed hospitalized cases and 3974 test-negative controls were included. Influenza A was the predominant type (68.7%). Comorbidities were present in 40.8% of cases. Children with comorbidities were at increased odds of ICU admission, respiratory support, longer hospitalizations, and mortality. Specific comorbidities including neurological and cardiac conditions increasingly predisposed children to severe outcomes. Influenza vaccine coverage in influenza negative children with and without comorbidities was low (33.5% and 17.9%, respectively). Coverage improved following introduction of universal influenza vaccine programs for children <5 years. Similar vaccine effectiveness was demonstrated in children with (55% [95% confidence interval (CI): 45; 63%]) and without comorbidities (57% [(95%CI: 44; 67%]).

CONCLUSIONS

Comorbidities were present in 40.8% of influenza-confirmed admissions and were associated with more severe outcomes. Children with comorbidities were more likely experience severe influenza with ICU admission, mechanical ventilation, and in-hospital morality. Despite demonstrated vaccine effectiveness in those with and without comorbidities, vaccine coverage was suboptimal. Interventions to increase vaccination are expected to reduce severe influenza outcomes.

A rapid global review of strategies to improve influenza vaccination uptake in Australia

This study aimed to identify effective strategies for improving the uptake of influenza vaccination and to inform recommendations for influenza vaccination programs in Australia. A rapid systematic review was conducted to assimilate and synthesize peer-reviewed articles identified in PubMed. The National Health and Medical Research Council (NHMRC) Hierarchy of Evidence was used to appraise the quality of evidence. A systematic search identified 4373 articles and 52 that met the inclusion criteria were included. The evidence suggests influenza vaccination uptake may be improved by interventions that (1) increase community/patient demand and access to influenza vaccine and overcome practice-related barriers; (2) reinforce the critical role healthcare providers play in driving influenza vaccination uptake. Strategies such as standing orders, reminder and recall efforts were successful in improving influenza vaccination rates. Community pharmacies, particularly in regional/remote areas, are well positioned to improve influenza vaccine coverage. The findings of this rapid review can be utilized to improve the performance of influenza immunization programs in Australia and other countries with comparable programs; and recommend priorities for future evaluation of interventions to improve influenza vaccination uptake.