Parental concerns and uptake of childhood vaccines in rural Tanzania - a mixed methods study

Population-based cross-sectional study of factors influencing full vaccination status of children aged 12- 23 months in a rural district of the Upper East Region, Ghana

BACKGROUND

Achieving universal health coverage includes ensuring that children have access to vaccines that are of high quality, safe, efficacious, and affordable. The Immunisation Agenda 2030 aims to expand services to zero-dose and incompletely vaccinated children and reduce immunisation rate disparities as a contribution to vaccination equity. This study explored the factors influencing full vaccination status among children aged 12 - 23 months in a rural district of the Upper East Region of Ghana.

METHODS

A population-based cross-sectional study was conducted among carers of children aged 12 -23 months in the Kassena Nankana West district. A multistage sampling technique was used to select 360 carers. Information regarding the vaccination status of children was gathered through a combination of children's health record books and carers' recollections. Information on potential determinants was also systematically collected for analysis in Stata version 15.0.

RESULTS

The results showed that 76.9% (95% CI: 72.3 - 81.0) of children had full vaccinations per the national schedule. All children received at least one vaccination. A higher percentage of carers with incompletely vaccinated children reported that they had travelled with their children as the primary reason for missing certain vaccine doses. Full vaccination status was significantly associated with secondary (aOR = 2.60; 95% CI: 1.20-5.63) and tertiary (aOR = 3.98, 95% CI: 1.34-11.84) maternal educational level, being in a partnership relationship (aOR = 2.09, 95% CI: 1.03-4.25), and residing in close proximity to healthcare facilities (aOR = 0.41, 95% CI: 0.21-0.80).

CONCLUSIONS

Our study found that nearly one-quarter of children aged 12-23 months in the study setting are underserved with vaccination services for a variety of reasons. Effectively reaching these children will require strengthening health systems, including eliminating vaccine shortages, addressing the unique challenges faced by unmarried women with children aged 12-23 months, and improving accessibility to vaccination services.

Interactive Narrative-Based Digital Health Interventions for Vaccine Communication: Protocol for a Scoping Review

BACKGROUND

Interactive narrative-based digital health interventions hold promise for effectively addressing the complex determinants of vaccine hesitancy and promoting effective communication across a wide range of settings and vaccine types. Synthesizing evidence related to the implementation and evaluation of these interventions could offer valuable perspectives for shaping future strategies in vaccine communication. Prior systematic and scoping reviews have examined narrative-based vaccine communication interventions but not the inclusion of interactivity in such interventions.

OBJECTIVE

The overall objective of the scoping review is to summarize the evidence on the use of interactive narrative-based digital health interventions for vaccine communication. Specific research questions focus on describing the use of interactive narrative-based digital health interventions (RQ1), describing evaluations of the impact of interactive narrative-based digital health interventions on promoting vaccine uptake (RQ2), and factors associated with their implementation (RQ3).

METHODS

A detailed search string will be used to search the following databases for records that are relevant to the review questions: PubMed, Embase, Scopus, Web of Science, CINAHL, and PsycINFO. Two reviewers will independently screen the titles and abstracts of identified records against the predefined eligibility criteria. Subsequently, eligible records will undergo comprehensive full-text screening by 2 independent reviewers to assess their relevance to review questions. A data charting tool will be developed and used to extract relevant information from the included articles. The extracted information will be analyzed following the review questions and presented as a narrative summary. Tabular or graphical representations will be used to display review findings, as relevant.

RESULTS

Public health informationists were consulted to develop the detailed search strategy. The final search string comprised terms related to narrative communication, digital health, and vaccines. The search string was customized to each proposed publication database and implemented on April 18, 2023. A total of 4474 unique records were identified using the search strategy and imported into the Covidence (Veritas Health Innovation Ltd) review management software for title and abstract screening. Title and abstract screening of identified records are ongoing as of December 29, 2023.

CONCLUSIONS

To our knowledge, this will be the first scoping review to investigate the features of interactive narrative-based digital health interventions and their role in vaccine communication. The goal of this study is to provide a comprehensive overview of the current research landscape and identify prevailing gaps in knowledge. The findings will provide insights for future research and development of novel applications of interactive narrative-based digital health vaccine communication interventions.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51137.

Leveraging Community Health Workers and a Responsive Digital Health System to Improve Vaccination Coverage and Timeliness in Resource-Limited Settings: Protocol for a Cluster Randomized Type 1 Effectiveness-Implementation Hybrid Study

BACKGROUND

Tanzania is 1 of 20 countries where the majority of unvaccinated and undervaccinated children reside. Prior research identified substantial rural-urban disparities in the coverage and timeliness of childhood vaccinations in Tanzania, with children in rural settings being more likely to receive delayed or no vaccinations. Further research is necessary to identify effective and scalable interventions that can bridge rural-urban gaps in childhood vaccination while accounting for multifaceted barriers to vaccination.

OBJECTIVE

This protocol describes a type 1 effectiveness-implementation hybrid study to evaluate Chanjo Kwa Wakati (timely vaccination in Kiswahili), a community-based digital health intervention to improve vaccination timeliness. The intervention combines human resources (community health workers), low-cost digital strategies (electronic communication, digital case management, and task automation), a vaccination knowledge intervention, and insights from behavioral economics (reminders and incentives) to promote timely childhood vaccinations.

METHODS

The study will be conducted in 2 predominantly rural regions in Tanzania with large numbers of unvaccinated or undervaccinated children: Shinyanga and Mwanza. Forty rural health facilities and their catchment areas (clusters) will be randomized to an early or delayed onset study arm. From each cluster, 3 cohorts of mother-child dyads (1 retrospective cohort and 2 prospective cohorts) will be enrolled in the study. The timeliness and coverage of all vaccinations recommended during the first year of life will be observed for 1200 children (n=600, 50% intervention group children and n=600, 50% nonintervention group children). The primary effectiveness outcome will be the timeliness of the third dose of the pentavalent vaccine (Penta3). Quantitative surveys, vaccination records, study logs, fidelity checklists, and qualitative interviews with mothers and key informants will inform the 5 constructs of the reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework. The results will be used to develop an implementation blueprint to guide future adaptations and scale-up of Chanjo Kwa Wakati.

RESULTS

The study was funded in August 2022. Data collection is expected to last from February 2024 to July 2027.

CONCLUSIONS

This study will address the lack of rigorous evidence on the effectiveness of community-based digital health interventions for promoting vaccination coverage and timeliness among children from sub-Saharan Africa and identify potential implementation strategies to facilitate the deployment of vaccination promotion interventions in low- and middle-income countries.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06024317; https://www.clinicaltrials.gov/study/NCT06024317.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/52523.

A cross-sectional study on the reasons for vaccine hesitancy in children under seven years of age in Isfahan, Iran

Introduction

The diminution in vaccination coverage in recent years has contributed to the reappearance of infectious diseases, and vaccine hesitancy is one of the main causes. As a result, we investigated the causes of vaccine hesitancy in children.

Materials and methods

This descriptive-analytical study was conducted cross-sectionally in 27 comprehensive health service centers in Isfahan City from June to October 2022. This study included Iranian families living in Isfahan who did not vaccinate their children by the due date. A researcher-made questionnaire collected data on children's vaccine hesitancy after verifying validity and reliability over the phone and in person by the researcher. The mothers completed informed consent. Independent T-tests, Pearson's correlation coefficient, analysis of variance, and a generalized linear model were used to analyze the data.

Findings

Finally, 298 families participated in the study, 34.3% refused, and 65.7% delayed their child's vaccination. Vaccination was hesitant due to the child being sick at the time of injection (57.3%), believing that vaccination is not necessary to prevent uncommon diseases (49%), and being concerned about severe side effects caused by the vaccine (48.7%). Vaccine hesitancy among mothers with bachelor's degrees and families less than one kilometer from the health center was significantly less than among others. Additionally, Vaccines at birth, four, six, twelve, and eighteen months, and six-year-old vaccines were associated with vaccine hesitancy.

Conclusion

Children's illness at the time of vaccination, the belief that vaccination is unnecessary to prevent uncommon diseases, and the worry about severe complications were among the most common reasons for vaccine hesitancy. Mother's education, distance to the health center, and vaccine type were associated with vaccine hesitancy.

Understanding Sociodemographic Factors and Reasons Associated with COVID-19 Vaccination Hesitance among Adults in Tanzania: A Mixed-Method Approach

Although studies on COVID-19 vaccine hesitancy are being undertaken widely worldwide, there is limited evidence in Tanzania. This study aims to assess the sociodemographic factors associated with COVID-19 vaccine hesitancy and the reasons given by unvaccinated study participants. We conducted a mixed-method cross-sectional study with two components-health facilities and communities-between March and September 2022. A structured questionnaire and in-depth interviews were used to collect quantitative and qualitative data, respectively. A total of 1,508 individuals agreed to participate in the survey and explained why they had not vaccinated against COVID-19. Of these participants, 62% indicated they would accept the vaccine, whereas 38% expressed skepticism. In a multivariate regression analysis, adult study participants 40 years and older were significantly more likely to report not intending to be vaccinated (adjusted odds ratio [AOR], 1.28; 95% CI, 1.01-1.61; P = 0.04) than youth and middle-aged study participants between 18 and 40 years. Furthermore, female study participants had a greater likelihood of not intending to be vaccinated (AOR, 1.51; 95% CI, 1.19-1.90; P = 0.001) than male study participants. The study identified fear of safety and short-term side effects, and lack of trust of the COVID-19 vaccine; belief in spiritual or religious views; and belief in local remedies and other precautions or preventive measures as the major contributors to COVID-19 vaccine hesitancy in Tanzania. Further empirical studies are needed to confirm these findings and to understand more fully the reasons for vaccine hesitancy in different demographic groups.

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 < 0.001), high-income countries residents (50.6%, p < 0.001), and mothers with higher educational levels (52.1%, p < 0.001). Parents of school-aged children (5–9 years) (55.6%, p < 0.001), children free from any comorbidities (52.5%, p < 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 < 0.001), in addition to parents who were not vaccinated against influenza (57.1%, p < 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 < 0.001), meanwhile those who used social media as their source of health information showed a significantly higher VH (57.2%, p < 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.

Tetanus and Diphtheria Seroprotection among Children Younger Than 15 Years in Nigeria, 2018: Who Are the Unprotected Children?

Serological surveys provide an objective biological measure of population immunity, and tetanus serological surveys can also assess vaccination coverage. We undertook a national assessment of immunity to tetanus and diphtheria among Nigerian children aged <15 years using stored specimens collected during the 2018 Nigeria HIV/AIDS Indicator and Impact Survey, a national cross-sectional household-based survey. We used a validated multiplex bead assay to test for tetanus and diphtheria toxoid-antibodies. In total, 31,456 specimens were tested. Overall, 70.9% and 84.3% of children aged <15 years had at least minimal seroprotection (≥0.01 IU/mL) against tetanus and diphtheria, respectively. Seroprotection was lowest in the north west and north east zones. Factors associated with increased tetanus seroprotection included living in the southern geopolitical zones, urban residence, and higher wealth quintiles (p < 0.001). Full seroprotection (≥0.1 IU/mL) was the same for tetanus (42.2%) and diphtheria (41.7%), while long-term seroprotection (≥1 IU/mL) was 15.1% for tetanus and 6.0% for diphtheria. Full- and long-term seroprotection were higher in boys compared to girls (p < 0.001). Achieving high infant vaccination coverage by targeting specific geographic areas and socio-economic groups and introducing tetanus and diphtheria booster doses in childhood and adolescence are needed to achieve lifelong protection against tetanus and diphtheria and prevent maternal and neonatal tetanus.

Is the intention to vaccinate enough? Systematic variation in the value of timely vaccinations and preferences for monetary vs non-monetary incentives among pregnant women in southern Tanzania

Background

Globally, approximately 19.7 million children remain under-vaccinated; many more receive delayed vaccinations. Sustained progress towards global vaccination targets requires overcoming, or compensating for, incrementally greater barriers to vaccinating hard-to-reach and hard-to-vaccinate children. We prospectively assessed pregnant women's valuations of routine childhood vaccinations and preferences for alternative incentives to inform interventions aiming to increase vaccination coverage and timeliness in southern Tanzania.

Methods

Between August and December 2017, 406 women in their last trimester of pregnancy were enrolled from health facilities and communities in the Mtwara region of Tanzania and asked contingent valuation questions about their willingness to vaccinate their child if they were (a) given an incentive, or (b) facing a cost for each vaccination. Interval censored regressions assessed correlates of women's willingness to pay (WTP) for timely vaccinations. Participants were asked to rank monetary and non-monetary incentive options for the timely vaccination of their children.

Findings

All women expected to get their children vaccinated according to the recommended schedule, even without incentives. Nearly all women (393; 96.8 %) were willing to pay for vaccinations. The average WTP was Tanzania Shilling (Tsh) 3,066 (95 % confidence interval Tsh 2,523-3,610; 1 USD ∼ Tsh 2,200) for each vaccination. Women's valuations of timely vaccinations varied significantly with vaccine-related knowledge and attitudes, economic status, and rural vs urban residence. Women tended to prefer non-monetary over monetary incentives for the timely vaccination of their children.

Interpretation

Women placed a high value on timely childhood vaccinations, suggesting that unexpected system-level barriers rather than individual-level demand factors are likely to be the primary drivers of missed vaccinations. Systematic variation in the value of vaccinations across women reflects variation in perceived benefits and opportunity costs. In this setting, nonmonetary incentives and other interventions to increase demand and compensate for system-level barriers hold significant potential for improving vaccination coverage and timeliness.

ClinicalTrialsgov Protocol

NCT03252288.

What Motivates People to Receive Continuous COVID-19 Vaccine Booster Shots? An Expectation Confirmation Theory Perspective

(1) Background: Abundant evidence has shown that the COVID-19 vaccine booster is highly effective against the Omicron variant. It is of great practical significance to explore the factors influencing the intention to receive COVID-19 booster shots. (2) Methods: We introduced expectation confirmation theory as the basis to construct a model of the factors of the vaccination intention for COVID-19 vaccine boosters. We obtained two batches of questionnaires through Chinese social platforms, with a valid sample size of 572. To test the model, we used SmartPLS3.0 software for empirical analysis. (3) Results: In terms of the characteristics of the vaccine itself, perceived vaccine efficacy and perceived vaccine safety had significant positive effects on expectation confirmation. Regarding vaccination services, perceived vaccination convenience also had a significant positive effect on expectation confirmation. Expectation confirmation positively affected the vaccination intention for the COVID-19 vaccine boosters. Furthermore, the results showed two moderating effects: first, health consciousness negatively moderated the positive effect of perceived vaccine safety on expectation confirmation; second, the time interval since the last dose negatively moderated the positive effect of perceived vaccine efficacy on expectation confirmation. (4) Conclusions: Our research demonstrated that there is an expectation confirmation process for previous COVID-19 vaccines before people consider whether to obtain a booster shot. Perceived vaccine efficacy and perceived vaccine safety remained important factors in receiving COVID-19 booster shots, and our conclusions were consistent with previous literature. In this study, multiple dimensions such as distance and cost were used to measure perceived vaccination convenience. This new variable improve the explanatory power of the convenience of the vaccination service and enrich the variables of the factor model of vaccination intention. In addition, the moderating effects of health consciousness and time interval were found. The findings can provide a theoretical reference for public health institutions to help them understand the formation process of people's intention to receive the COVID-19 vaccine booster.

Beyond coverage: Rural-urban disparities in the timeliness of childhood vaccinations in Tanzania

BACKGROUND

Timely vaccination maximizes efficacy for preventing infectious diseases. In the absence of national vaccination registries, representative sample survey data hold vital information on vaccination coverage and timeliness. This study characterizes vaccination coverage and timeliness in Tanzania and provides an analytic template to inform contextually relevant interventions and evaluate immunization programs.

METHODS

Cross-sectional data on 6,092 children under age 3 from the 2015-16 Tanzania Demographic and Health Survey were used to examine coverage and timeliness for 14 vaccine doses recommended in the first year of life. The Kaplan-Meier method was used to model time to vaccination. Cox proportional hazard models were used to examine factors associated with timely vaccination.

RESULTS

Substantial rural-urban disparities in vaccination coverage and timeliness were observed for all vaccines. Across 14 recommended doses, documented coverage ranged from 52 % to 79 %. Median vaccination delays lasted up to 35 days; gaps were larger among rural than urban children and for later doses in vaccine series. Among rural children, median delays exceeded 35 days for the 3rd doses of the polio, pentavalent, and pneumococcal vaccines. Median delays among urban children were < 21 days for all doses. Among rural and urban children, lower maternal education and delivery at home were associated with increased risk of delayed vaccination. In rural settings, less household wealth and greater distance to a health facility were also associated with increased risk of delayed vaccination.

DISCUSSION

This study highlights persistent gaps in uptake and timeliness of childhood vaccinations in Tanzania and substantial rural-urban disparities. While the results provide an informative situation assessment and outline strategies for identifying unvaccinated children, a national electronic registry is critical for comprehensive assessments of the performance of vaccination programs. The timeliness measure employed in this study-the amount of time children are un- or undervaccinated-may serve as a sensitive performance metric for these programs.

Association of community engagement with vaccination confidence and uptake: A cross-sectional survey in Sierra Leone, 2019

Background

The 2014-2016 Ebola epidemic disrupted childhood immunization in Sierra Leone, Liberia, and Guinea. After the epidemic, the Government of Sierra Leone prioritized community engagement to increase vaccination confidence and uptake. To support these efforts, we examined potential drivers of vaccination confidence and uptake in Sierra Leone.

Methods

We conducted a population-based household survey with primary caregivers of children in a birth cohort of 12 to 23 months in four districts with low vaccination coverage in Sierra Leone in 2019. Modified Poisson regression modeling with robust variance estimation was used to examine if perceived community engagement in planning the immunization program in the community was associated with vaccination confidence and having a fully vaccinated child.

Results

The sample comprised 621 age-eligible children and their caregivers (91% response rate). Half of the caregivers (52%) reported that it usually takes too long to get to the vaccination site, and 36% perceived that health workers expect money for vaccination services that are supposed to be given at no charge. When mothers were the decision-makers of the children’s vaccination, 80% of the children were fully vaccinated versus 69% when fathers were the decision-makers and 56% when other relatives were the decision-makers. Caregivers with high confidence in vaccination were more likely to have fully vaccinated children compared to caregivers with low confidence (78% versus 53%). For example, caregivers who thought vaccines are ‘very much’ safe were more likely to have fully vaccinated children than those who thought vaccines are ‘somewhat’ safe (76% versus 48%). Overall, 53% of caregivers perceived high level of community engagement, 41% perceived medium level of engagement, and 6% perceived low level of engagement. Perceiving high community engagement was associated with expressing high vaccination confidence (adjusted prevalence ratio (aPR) = 2.60; 95% confidence interval (CI) = 1.67-4.04) and having a fully vaccinated child (aPR = 1.67; 95% CI = 1.18-2.38).

Conclusions

In these four low coverage districts in Sierra Leone, the perceived level of community engagement was strongly associated with vaccination confidence among caregivers and vaccination uptake among children. We have provided exploratory cross-sectional evidence to inform future longitudinal assessments to further investigate the potential causal effect of community engagement on vaccination confidence and uptake.

COVID-19 Impact on Disparity in Childhood Immunization in Low- and Middle-Income Countries Through the Lens of Historical Pandemics

Purpose of Review

The COVID-19 pandemic, since 2020, has affected health care services and access globally. Although the entire impact of COVID-19 pandemic on existing global public health is yet to be fully seen, the impact of COVID-19 pandemic on global childhood immunization programs is of particular importance.

Recent Findings

Disruptions to service delivery due to lockdowns, challenges in vaccination programs, vaccine misinformation and hesitancy, and political and social economic inequalities all posed a threat to existing childhood immunization programs. These potential threats were especially critical in LMIC where childhood immunization programs tend to experience suboptimal implementation.

Summary

This review provides an overview of childhood immunizations and discusses past pandemics particularly in LMIC, factors contributing to disparities in childhood immunizations, and reviews potential lessons to be learned from past pandemics. Vaccine hesitancy, social determinants of health, and best practices to help lessen the pandemic's influence are also further elaborated. To address current challenges that hindered the progress made in prevention of childhood illnesses through vaccination campaigns and increased vaccine availability, lessons learned through best practices explored from past pandemics must be examined to mitigate impact of COVID-19 on childhood immunization and in turn conserve health and improve economic well-being of children especially in LMIC.

Altered Lipid Profiles and Vaccine Induced-Humoral Responses in Children Living With HIV on Antiretroviral Therapy in Tanzania

People living with HIV, even under therapy, have a high burden of age-related co-morbidities including an increased risk of dyslipidemia (which often predisposes to cardiovascular diseases) and immune-aging. In this study, lipid profiles and antibody responses to measles and pertussis toxin vaccines were compared between ART experienced HIV+ children (n=64) aged 5-10 years, and their age- and sex-matched HIV- controls (n=47). Prevalence of high-density lipoprotein cholesterol (HDL-c) and triglyceride-driven dyslipidemia was higher among treated HIV+ children than in controls (51.6% vs 27.7% respectively, p < 0.019). In a multivariate Poisson regression model adjusted for age, sex and BMI, the association between low HDL-c, hypertriglyceridemia and HIV remained significantly high (for HDL-c: ARR: 0.89, 95% CI: 0.82 - 0.96, p = 0.003; for triglycerides: ARR: 1.54, 95% CI: 1.31 - 1.81, p < 0.001). Among HIV+ children, the use of lopinavir/ritonavir, a protease-based antiretroviral therapy was also associated elevation of triglyceride levels (p = 0.032). Also, HIV+ children had a 2.8-fold reduction of anti-measles IgG titers and 17.1-fold reduction of anti-pertussis toxin IgG levels when compared to HIV- children. Our findings suggest that dyslipidemia and inadequate vaccine-induced antibody responses observed in this population of young African HIV+ children might increase their risk for premature onset of cardiovascular illnesses and acquisition of preventable diseases.

Exploring and Monitoring the Reasons for Hesitation with COVID-19 Vaccine Based on Social-Platform Text and Classification Algorithms

(1) Background: The COVID-19 pandemic is globally rampant, and it is the common goal of all countries to eliminate hesitation in taking the COVID-19 vaccine and achieve herd immunity as soon as possible. However, people are generally more hesitant about the COVID-19 vaccine than about other conventional vaccines, and exploring the specific reasons for hesitation with the COVID-19 vaccine is crucial. (2) Methods: this paper selected text data from a social platform to conduct qualitative analysis of the text to structure COVID-19 vaccine hesitancy reasons, and then conducted semiautomatic quantitative content analysis of the text through a supervised machine-learning method to classify them. (3) Results: on the basis of a large number of studies and news reports on vaccine hesitancy, we structured 12 types of the COVID-19 vaccine hesitancy reasons. Then, in the experiment, we conducted comparative analysis of three classifiers: support vector machine (SVM), logistic regression (LR), and naive Bayes classifier (NBC). Results show that the SVM classification model with TF-IDF and SMOTE had the best performance. (4) Conclusions: our study structured 12 types of COVID-19 vaccine hesitancy reasons through qualitative analysis, filling in the gaps of previous studies. At the same time, this work provides public health institutions with a monitoring tool to support efforts to mitigate and eliminate COVID-19 vaccine hesitancy.

COVID-19 Vaccine Hesitancy among Parents of Children and Adolescents Living in Brazil

Background: The immunization of large portions of populations in low/middle-income countries is considered one of the key measures to limit the development of new SARS-CoV-2 variants. However, parental vaccine hesitancy might be an important obstacle to pediatric vaccination. The aim of this survey was to study the prevalence and extent of COVID-19 vaccine hesitancy among parents of children and adolescents living in Brazil. Methods: Caregivers of children and adolescents referred to the emergency department of Hospital Estadual de Bauru, São Paulo (Brazil) were invited to fill in a validated questionnaire on vaccine hesitancy and to report their willingness for themselves and their offspring to receive a COVID-19 vaccine. Results: A total of 501 consecutive caregivers filled in the survey. Response rate was 100%. A minority (N = 14, 2.8%) of caregivers were hesitant about vaccines. Despite this, half of them declared they were willing to vaccinate their offspring against COVID-19. Conclusions: This survey identifies that vaccine hesitancy is very low among caregivers living in Brazil and that even many of the hesitant caregivers are willing to vaccinate their offspring against COVID-19. This study highlights the importance of offering the COVID-19 vaccination to the whole population, including subjects that present uncertainty about other vaccines.

Scared, powerless, insulted and embarrassed: hesitancy towards vaccines among caregivers in Cavite Province, the Philippines

BACKGROUND

Several studies have highlighted that vaccine hesitancy (VH) is among the most important threats to global health, especially in low- and middle-income countries, including the Philippines. However, there is a dearth of literature exploring family experiences of-or concerns related to-childhood vaccinations that gives voice to vaccine hesitant caregivers (VHCs) of small children. Here, we present insights from VHCs from the Philippines.

METHODS

This research draws on in-depth interviews (IDIs) with 44 VHCs who had previously delayed or refused vaccination for their children in rural and urban communities in Cavite Province, the Philippines. Amid the COVID-19 pandemic, we conducted IDIs via an online platform of the respondents' choosing (ie, Facebook messenger call, Skype and Zoom). All interviews were recorded, transcribed, translated and analysed drawing from the tenets of constructivist grounded theory. We use the social ecological model to structure our results.

RESULTS

Among the reasons for delay or refusal of childhood vaccinations, a fear of side effects emerged as the most salient concern, exacerbated by previous negative experiences (including trauma) from a dengue vaccine controversy in 2017. Respondents cited the dengue vaccine controversy as they expressed reluctance (regarding any new vaccines) and suspicion (towards school-based vaccination, the distribution channel used for the dengue vaccine). Heads of households opposing vaccines, perceptions that vaccines are non-essential and influences from the social and traditional media or neighbours contributed to further refusal and delay. Upon probing, VHCs recounted health system concerns particularly with regards to healthcare workers who are sometimes unable to answer their questions and can be dismissive or disrespectful regarding caregivers' concerns.

CONCLUSION

Understanding VH from the lens of VHCs highlights pathways for interventions to regain trust and bolster confidence towards vaccines. Our findings may serve as linchpins in the development of VH interventions aiming at changing behaviour on a population scale.