An Exploration of COVID-19 Impact and Vaccine Hesitancy in Parents of Pediatric Hematopoietic Stem Cell Transplant (HCT) Recipients

COVID-19 Vaccine Hesitancy among Parents of Children Younger than 12 Years: Experience from a Tertiary Outpatient Clinic

This study explored parents' attitudes towards vaccinating their children against COVID-19 and the rate of vaccine hesitancy in Oman. A cross-sectional, online, self-administered questionnaire, previously validated and administered between June 2021 and May 2022, was used. The questionnaire consisted of nine items. Parents of children younger than 12 years were eligible for participation. A total of 384 participants, including 207 males (54%), completed the questionnaire, resulting in an 86% response rate (384/447). The results showed that 69% of participants were hesitant to vaccinate their children aged 1-11 years. In parents of children aged 1-4 years, vaccination status was significantly associated with vaccine hesitancy (odds ratio [OR], 0.116; 95% confidence interval [CI], 0.044-0.306; p = 0.001). Furthermore, after multivariable analysis, compared to the fathers, mothers were significantly less likely to be associated with vaccine hesitancy (OR, 0.451; 95% CI, 0.240-0.848; p = 0.013).

Impact of a booster dose on SARS-CoV2 mRNA vaccine-specific humoral-, B- and T cell immunity in pediatric stem cell transplant recipients

Stem cell transplant recipients (SCTR) are imperiled to increased risks after SARS-CoV2 infection, supporting the need for effective vaccination strategies for this vulnerable group. With respect to pediatric patients, data on immunogenicity of SARS-CoV2 mRNA-based vaccination is limited. We therefore comprehensively examined specific humoral, B- and T cell responses in a cohort of 2-19 year old SCTR after the second and third vaccine dose. Only after booster vaccination, transplant recipients reached similar levels of vaccine-specific IgG, IgA and neutralizing antibodies against omicron variant as age-matched controls. Although frequencies of SARS-CoV2 specific B cells increased after the third dose, they were still fourfold reduced in patients compared to controls. Overall, the majority of individuals enrolled mounted SARS-CoV2 Spike protein-specific CD4+ T helper cell responses with patients showing significantly higher portions than controls after the third dose. With respect to functionality, however, SCTR were characterized by reduced frequencies of specific interferon gamma producing CD4+ T cells, along with an increase in IL-2 producers. In summary, our data identify distinct quantitative and qualitative impairments within the SARS-CoV2 vaccination specific B- and CD4+ T cell compartments. More importantly, humoral analyses highlight the need for a booster vaccination of SCTR particularly for development of neutralizing antibodies.

Review: Factors influencing parents' decisions to vaccinate children against COVID-19

INTRODUCTION

Vaccination is a cornerstone of public health, significantly safeguarding children's health. Despite the imperative of achieving extensive COVID-19 vaccine coverage, vaccine hesitancy poses a major challenge.

OBJECTIVE

This review's aim is to analyze parental COVID-19 vaccine acceptance and hesitancy during the COVID-19 pandemic and elucidate the factors that influenced their decisions.

METHODS

A search of Medline (PubMed), Embase, and Psycinfo was conducted on February 1, 2022. The inclusion criteria were limited to observational studies that specifically evaluated parental COVID-19 vaccine acceptance or hesitancy for children, published in English. Studies that did not focus on this specific assessment, interventional studies, clinical trials, and secondary literature were excluded.

RESULTS

In reviewing 27 articles, parental vaccination acceptance rates were found to be different worldwide. Despite this, most of the articles found the same set of factors impacting parental COVID-19 vaccine acceptance and hesitancy. Parents' age, education, race, children's age, and annual household income were the main sociodemographic factors in vaccination decisions. Other common factors were the perceived risk and benefits of the COVID-19 vaccine, the source of information, parents' acceptance of receiving vaccinations themselves, and previous acceptance of the influenza vaccine. By reviewing parents' willingness to accept the COVID-19 vaccine for their children, it became clear that a lack of information about vaccine safety and efficacy was the most common factor affecting their decision.

CONCLUSION

This review identified critical factors affecting parents' vaccination behavior for their children. Awareness of these factors may reduce parents' COVID-19 vaccine refusal for their children and guide future planning and development of public health studies.

The Association Between Pediatric COVID-19 Vaccination and Socioeconomic Position: Nested Case-Control Study From the Pedianet Veneto Cohort

BACKGROUND

The success of pediatric COVID-19 vaccination strongly depends on parents' willingness to vaccinate their children. To date, the role of socioeconomic position (SEP) in pediatric COVID-19 vaccination has not been thoroughly examined.

OBJECTIVE

We evaluated the association between COVID-19 vaccination and SEP in a large pediatric cohort.

METHODS

A case-control study design nested into a pediatric cohort of children born between 2007 and 2017, living in the Veneto Region and followed up to at least January 1, 2022, was adopted. Data on children were collected from the Pedianet database and linked with the regional COVID-19 registry. Each child vaccinated with at least one dose of any COVID-19 vaccine between July 1, 2021, and March 31, 2022, was matched by sex, year of birth, and family pediatrician to up to 5 unvaccinated children. Unvaccinated children with a positive outcome on the swab test within 180 days before the index date were excluded from the analyses. Children were geo-referenced to determine their area deprivation index (ADI)-a social and material deprivation measure calculated at the census block level and consisting of 5 socioeconomic items. The index was then categorized in quintiles based on the regional ADI level. The association between ADI quintiles and vaccination status was measured using conditioned logistic regression models to estimate odds ratios and the corresponding 95% CIs. Quantile-g-computation regression models were applied to develop a weighted combination of the individual items to estimate how much each component influenced the likelihood of vaccination. All analyses were stratified by age at vaccination (5-11 and 12-14 years).

RESULTS

The study population consisted of 6475 vaccinated children, who were matched with 32,124 unvaccinated children. Increasing area deprivation was associated with a lower probability of being vaccinated, with approximately a linear dose-response relationship. Children in the highest deprivation quintile were 36% less likely to receive a COVID-19 vaccine than those with the lowest area deprivation (95% CI 0.59-0.70). The results were similar in the 2 age groups, with a slightly stronger association in 5-11-year-old children. When assessing the effects of the weighted combination of the individual items, a quintile increase was associated with a 17% decrease in the probability of being vaccinated (95% CI 0.80-0.86). The conditions that influenced the probability of vaccination the most were living on rent, being unemployed, and being born in single-parent families.

CONCLUSIONS

This study has shown a significant reduction in the likelihood of receiving a COVID-19 vaccine among children living in areas characterized by a lower SEP. Findings were robust among multiple analyses and definitions of the deprivation index. These findings suggest that SEP plays an important role in vaccination coverage, emphasizing the need to promote targeted public health efforts to ensure global vaccine equity.

COVID-19 mRNA Vaccine Tolerance and Immunogenicity in Hematopoietic Stem Cell Transplantation Recipients Aged 5-11 Years Old-Non-Randomized Clinical Trial

The SARS-CoV-2 pandemic had a devastating impact on the world’s population in the years 2020−2022. The rapid development of vaccines enabled a reduction in the mortality and morbidity of COVID-19, but there are limited data about their effects on immunocompromised children. The aim of this prospective study was to evaluate the safety and efficacy of the mRNA BNT162b2 (Pfizer/Biontech) vaccine in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Material and methods: Two cohorts of 34 children after allo-HSCT and 35 healthy children aged 5−11 years were vaccinated with two doses of the mRNA BNT162b2 (10 µg) vaccine. All children were evaluated for adverse effects with electronic surveys and the immunogenicity of the vaccine was assessed with anti-SARS-CoV-2 IgG titer measurements. Results: All reported adverse events (AEs) were classified as mild. The most common AE was pain at the injection site. All the other AEs (both local and systemic) were rarely reported (<15% patients). Both groups showed a similar response in anti-SARS-CoV-2 IgG production. Patients after allo-HSCT that were undergoing immunosuppressive treatment presented a poorer immunological response than patients off of treatment. Time since HSCT, patient age, lymphocyte count, and total IgG concentration did not correlate with initial/post-vaccination anti-SARS-CoV-2 IgG titers. Most patients who were eligible for a third dose of the vaccine had an excellent humoral response observed after two vaccine doses. Conclusions: The COVID-19 mRNA BNT162b2 vaccine is very well tolerated and highly immunogenic in 5−11-year-old children after HSCT. Children >2 years of age after HSCT who did not receive immunosuppressive treatment presented excellent antibody production after two doses of the vaccine, but children on immunosuppression may require a more intense vaccination schedule.

Adherence to Sars-CoV2 vaccination in hematological patients

Background

SARS-CoV2 vaccination efficiently prevents severe COVID-19, although hematological patients, particularly under therapy, respond less well. Besides vaccine efficacy, adherence to vaccination is essential for ensuring adequate protection of this vulnerable population.

Methods

We evaluated the impact of a program aimed at maximizing patient adherence by comparing the rate of SARS-CoV2 vaccination of our hematological patients and a matched sample of the general population.

Results

Vaccination rates were 88.9% among 2,156 patients, aged 65.2 ± 15.8 years (M ± SD, range 19-86 years). Rates differed considerably with age, i.e. 84.2% between 18-64 years and 92.4% above 65 years (p<0.0001), but not with sex. In the general population, rates were 76.3% overall, 73.0% between 18-64 and 86.7% above 65 years, all significantly lower than among patients, overall (Standardized Incidence ratio (SIR) 1.17; 95%CI 1.12-1.22, p<0.0001) as well as among younger (SIR 1.15; 1.07-1.24, p<0.0001) or older (SIR 1.06; 1.00-1.13, p=0.046) people. Vaccination rates increased to 92.2% overall (SIR 1.21; 1.16-1.27, p<0.0001), 88.5% in younger (SIR 1.21; 1.13-1.30, p<0.0001) and 94.8% in older (SIR 1.09; 1.03-1.12, p=0.0043) patients, after excluding those with medical contraindications, and further to 95.6% overall (SIR 1.26; 1.20-1.32, p<0.0001), 93.8% in younger (SIR 1.29; 1.20-1.38, p<0.0001) and 96.9% in older (SIR 1.11; 1.05-1.18, p=0.0004) patients, after excluding those not seen in hematology in 2021.

Conclusions

Vaccination rates were significantly higher in hematological patients compared to the general population regardless of age, sex and municipality. Acceptance of Covid vaccines by hematological patients may be improved by targeted information campaigns carried out by trusted health care professionals.

COVID-19 vaccine counseling and safety assessment in children and teenagers with underlying medical conditions in China: a single center study

Safety concerns about novel vaccines and necessity of COVID-19 vaccination for children, especially with underlying medical conditions, are the obstacle of COVID-19 vaccination program among pediatric population. The study was conducted to investigate the vaccine hesitancy reasons among the parents, and to monitor the adverse events of inactivated COVID-19 vaccines in children and teenagers with underlying medical conditions in China. Children with underlying medical conditions encountered to the Immunization Advisory Clinic for COVID-19 vaccine counseling were enrolled. They were given immunization recommendation and followed up at 72 h and 28 d after immunization to monitor the immunization compliance after consultation and adverse events. A total of 324 children aged 3–17 y were included. The top three primary medical conditions for counseling were allergy (33.6%), neurological diseases (31.2%) and rheumatic diseases (8.3%). COVID-19 vaccination was promptly recommended for 242 (74.7%) children. Seventy-one (65.7%) children who had allergy issues were recommend to take vaccination, which was significantly lower than that of other medical conditions (p < .05). The follow-up record showed that 180 children received 340 doses of inactivated COVID-19 vaccine after consultation. Overall, 39 (21.6%) children reported at least one adverse event within 28 d of either vaccination. No serious adverse reactions were observed. No difference of adverse effects between the first dose and the second dose of vaccination except fever. Parents’ hesitancy in COVID-19 vaccination for children with underling medical conditions are mainly due to the safety concerns. Specialist consultation is helpful to improve the vaccine uptake.