Vaccination against influenza at a European pediatric cancer center: immunization rates and attitudes among staff, patients, and their families

Lessons learnt from influenza vaccination in immunocompromised children undergoing treatment for cancer

Influenza infection contributes substantially to global morbidity and mortality, with children undergoing treatment for cancer among the most vulnerable due to immunosuppression associated with disease and treatment. However, influenza remains one of the most common vaccine-preventable diseases. Despite international guidelines recommending inactivated influenza vaccination on the basis of data supporting efficacy and an excellent safety profile in this population, uptake has often been suboptimal due to persisting hesitancy among both patients and oncologists regarding the ability of the vaccine to mount a sufficient immune response, the optimal vaccine schedule and timing, and the best method to assess response in immunocompromised populations. In this Review, we discuss the evidence regarding influenza vaccination in children with cancer, factors that influence response, and highlight strategies to optimise vaccination. Host immune factors play a substantial role, thus principles learnt from influenza vaccination can be broadly applied for the use of inactivated vaccines in children with cancer.

Vaccination against influenza: Coverage and adherence in children under 15 years with high-risk medical conditions in the Community of Madrid

INTRODUCTION

Vaccination against influenza is indicated in children at risk of complications or severe disease. The objective of this study was to describe the percentage of children aged less than 15 years with risk conditions vaccinated against influenza in the Community of Madrid, and to analyze the factors associated with adherence to vaccination throughout 3 vaccination campaigns.

MATERIALS AND METHODS

Population-based cross-sectional observational study of children aged 6 months to 14 years with conditions that indicated influenza vaccination at the beginning of the 2018-2019 campaign. Electronic population registers were used. We described the percentage of children vaccinated in 3 consecutive campaigns, and assessed the association of adherence to vaccination with demographic and socioeconomic variables and risk conditions using bivariate and multivariate analysis.

RESULTS

The vaccination coverage was 15.6% in the 2018-2019 campaign. The adherence to vaccination was 65.9%. The variables associated with greater adherence were age greater than 2 years, especially in the 6-10 years group (aOR = 1.63; 95% CI, 1.43-1.85) and presenting more than one risk condition, especially 3 or more diseases (aOR = 1.80; 95% CI, 1.00-3.26). Diabetes mellitus was the disease associated most strongly with adherence (aOR = 2.15; 95% CI, 1.74-2.65). Adherence was lower in the immigrant population (aOR = 0.43; 95% CI, 0.36-0.51). We found no association between vaccination adherence and sex or socioeconomic status.

CONCLUSIONS

Vaccination coverage and adherence were suboptimal. Adherence to vaccination against influenza is associated with demographic and clinical conditions. Strategies need to be established to increase vaccination in children, with greater involvement of professionals and education of parents.

Prevalence of pain and fear as barriers to vaccination in children - Systematic review and meta-analysis

BACKGROUND

Injection-related pain and fear are common adverse reactions in children undergoing vaccination and influence vaccine acceptance. Despite the large body of literature on sources of vaccine non-compliance, there is no estimate of the prevalence of pain and fear as contributing factors. The objective was to estimate the prevalence of injection pain or fear of needles as barriers to childhood (i.e., 0-18 years) vaccination.

METHODS

Four databases were searched from inception for relevant English and French articles until August 2021. In addition, the references of recent systematic reviews and all articles included in the review were hand searched. Article screening and data extractions were performed in duplicate. Studies were included if they reported on injection-related pain or fear of needles in children (0-18 years) using a checklist/closed-ended question(s). Results were stratified by respondent (parents or children), type of pediatric population (general or under-vaccinated), and relative importance of barrier (pain or needle fear as primary reason or any reason for under-vaccination). Prevalence rates of pain or needle fear were combined using a random effects model. Quality of included studies was assessed using the Joanna Briggs Institute critical appraisal checklist for prevalence data. Quality across studies was assessed using GRADE.

RESULTS

There were 26 studies with 45 prevalence estimates published between 1995 and 2021. For parent reports (of children) and children self-reported reasons for non-compliance, prevalence rates of pain or needle fear ranged from 5 to 13% in a general population and 8 to 28% in an under-vaccinated population, with a substantial variation in the prevalence estimates. There was no difference between category of respondent or relative importance on pain or needle fear prevalence rate. A regression model demonstrated an overall prevalence rate of pain or needle fear as an obstacle to vaccination of 8% in the general population and 18.3% in the under-vaccinated population. All evidence was very low in quality.

CONCLUSION

This is the first review to systematically quantify the prevalence and therefore, importance, of pain and needle fear as obstacles to vaccination in children around the world. Pain from injection or fear of needles were demonstrated to be sufficiently prevalent as barriers to vaccination in children to warrant attention. Addressing pain and fear has the potential to significantly improve vaccination acceptance.

Gaps in knowledge about the vaccine coverage of immunocompromised children: a scoping review

Immunocompromised children are at increased risk of severe illness from vaccine-preventable infections. However, inadequate vaccine coverage remains a concern. This scoping review sought to determine the current state of knowledge regarding vaccine coverage of immunocompromised children. Bibliographic databases were searched for primary research from any year. Data were analyzed quantitatively and narratively. Ninety-seven studies met inclusion criteria. The most commonly studied vaccines were pneumococcal (n = 46), influenza (n = 44), diphtheria/tetanus/pertussis/poliomyelitis/Haemophilus influenzae type B/hepatitis B-containing (n = 36), and measles- and/or mumps- and/or rubella-containing (n = 29). Immunocompromising conditions studied included cancer/stem cell transplants (n = 24), solid organ transplants (n = 23), sickle cell disease (n = 21), immunosuppressive therapy (n = 14), human immunodeficiency virus (n = 12), splenectomy (n = 4), and primary immunodeficiency (n = 2). As more children are treated with immunosuppressive therapies, it is critical to identify whether they are being appropriately vaccinated for age and condition. We identified gaps in the current state of knowledge for specific vaccine types in specific immunocompromised populations.

Seasonal influenza vaccination among cancer patients: A systematic review and meta-analysis of the determinants

Cancer patients are among high-risk individuals for whom seasonal influenza vaccine (SIV) is recommended, but rates of vaccination in this subpopulation remain suboptimal; even in jurisdictions with universal influenza vaccination programs. We sought to summarize the evidence to better understand the determinants of SIV uptake (vaccine receipt) among cancer patients. We searched MEDLINE, Embase, and CINAHL from 2000 to February 12, 2020, focusing on articles on the determinants of seasonal influenza vaccination among cancer patients, published in English. Study selection was conducted independently by 2 reviewers. One reviewer extracted data from the included studies and another reviewer checked the extracted data for errors. Outcomes were sociodemographic and health-related factors. We pooled adjusted results from studies using the inverse variance, random-effects method, and reported the odds ratios (OR) and their 95% confidence intervals (CI). Out of 2664 citations, 10 studies (mostly from USA and South Korea) met our eligibility criteria. Overall, being older (OR 2.23, 95% CI 1.46-3.38; I² 92.3%, [6 studies]), a nonsmoker (1.43, 1.32-1.51; I² 0%, [4 studies]), having a chronic illness (1.18, 1.07-1.29; I² 15.7%, [5 studies]), having had a medical check-up in the past year (1.75, 1.65-1.86; I² 0%, [2 studies]), and having health insurance (1.39, 1.13-1.72; I² 21.8%, [3 studies]) were associated with increased SIV uptake. Compared with being African-American, being Caucasian was also associated with increased SIV uptake (1.79, 1.47-2.13; I² 10.7%, [3 studies]). Limited evidence suggests seasonal influenza vaccination among cancer patients may be determined by some sociodemographic and health-related factors.

Understanding influenza vaccination rates and reasons for refusal in caregivers and household contacts of cancer patients

Cancer patients are at increased risk for morbidity and mortality from seasonal influenza but are known to respond poorly to influenza vaccination. This single-center survey suggests that approximately one-third of cancer patients and their caregivers and family did not receive the vaccine in the prior season. Patients felt strongly that caregiver vaccination was important, whereas caregivers' decisions did not appear to be affected by the patients' disease.

Influenza Vaccination Rates Among Parents and Health Care Personnel in a German Neonatology Department

The influenza vaccination is recommended for all German pregnant women and health care personnel (HCP). We are the first to publish vaccination rates of mothers of hospitalized newborns and HCP in neonatal units. Between September 2016 and March 2017, data were collected in our level-III neonatology department in this descriptive multidisciplinary study, using an anonymous questionnaire. As a result, 513 persons were asked to participate, including 330 parents and 183 HCP. We received an 80.3% (412/513) response rate, 87.3% (288/330), and 67.8% (124/183) from parents and HCP, respectively. Ten percent (16/160) of mothers and 4.7% (6/127) of fathers had been vaccinated in 2016–2017 and 54.4% (87/160) mothers and 52.2% (66/127) fathers ever in their lifetime. In 2016–2017, 51.2% (21/41) of physicians had been vaccinated, 25.5% (14/55) of nurses, and 50.0% (14/28) of other staff members. When comparing those who had more than five influenza vaccinations in their life time, physicians were at 43.9% (18/41) versus nurses at 10.9% (6/55) (p < 0.01), and other HCP at 7.4% (2/27) (p < 0.01). The influenza vaccine uptake rate of 10% in mothers of hospitalized neonates is disappointingly low, resulting in 90% of hospitalized neonates being potentially vulnerable to influenza infection at a time where the risk for influenza-related complication can be severe.