Reaching the Unreached: Exploring Factors Affecting Vaccine Uptake and Acceptance Amongst Zero-dose Children and Women in Bangladesh Using the World Health Organization’s Behavioral and Social Drivers Framework

Background 

An estimated 18 million children did not receive the first dose of diphtheria, tetanus, and pertussis-containing vaccine (DTP1) in 2021 ⁽¹⁾. In Bangladesh, although national DTP3 coverage was maintained at 93% or above during the pandemic ^(2)* immunization coverage varied widely between rural and urban areas. In the country, full vaccination coverage of children in urban areas (79%) falls behind rural coverage (85%), inverse to many other countries ⁽³⁾. High internal migration in urban slum areas makes it challenging to track children who are missed or who drop-out from routine immunization (RI) programs. As a result of gaps in vaccination coverage, several outbreaks of vaccine-preventable diseases have recently been reported in some districts of Bangladesh. 

Several sporadic short-term initiatives have increased childhood immunization in Bangladesh, such as household visits by health workers to address misinformation and stigma, information awareness campaigns, text message reminders and engaging volunteers to escort mothers to vaccination sites. However, there is limited information on the demographic characteristics of unvaccinated (“zero-dose”) children, whether caregivers are being exposed to recommendations about immunization, key barriers to acceptance and uptake, and actions needed to minimize these gaps.  

Understanding the behavioral and social drivers of vaccination, and why children are zero-dose, is important to develop tailored, impactful solutions. The World Health Organization’s (WHO’s) behavioral and social drivers (BeSD) of vaccination framework provides guidance and tools to identify factors associated with zero-dose children and understand barriers and opportunities to increase uptake ⁽⁴⁾. The BeSD framework can also assist with the identification of marginalized and excluded groups and missed communities. This study by the icddr,b in Bangladesh applied the BeSD framework to explore the factors affecting vaccine uptake and acceptance amongst zero-dose children and women in Bangladesh in the urban area of Rangpur. 

_{*According to Expanded Programme on Immunization (EPI) estimates.}

Research Questions

1. What is the prevalence of zero-dose (unvaccinated) children in the target urban areas? 
2. What is the prevalence of women aged 15–49 years in the target urban areas who have not received the tetanus toxoid (TT) vaccine? 
3. What are the factors affecting RI and TT vaccine uptake in the target populations? 
4. What are the perspectives of priority groups⁽²⁾ on barriers and enablers for the COVID-19 vaccine uptake and opinion on integrating the COVID-19 vaccine into the national immunization program?  

Objectives

• To estimate the prevalence of zero-dose children and identify groups of children who are at increased risk of being unvaccinated 

• To estimate the prevalence and identify groups of women aged 15–49 years who are at increased risk of not receiving TT vaccine 

• To understand the barriers and enablers of RI among children and TT vaccination among women aged 15–49 years old  

Methodology 

Research Design

A cross-sectional mixed-methods approach was used to examine the complex factors influencing vaccine acceptance and uptake. The prevalence of zero-dose children and TT vaccine coverage among women aged 15–49 years was assessed using the WHO BeSD framework (research questions 1 and 2). The BeSD tool was also employed to collect both survey and qualitative data to address research questions 3 and 4.  

Study Location

The study was conducted in three urban areas: Rangpur City Corporation (RpCC), Dhaka North City Corporation (DNCC) and Dhaka South City Corporation (DSCC). RpCC has one of the country’s lowest urban full vaccination rates, with only 77% coverage for the first dose of pentavalent vaccine and 70% full vaccination coverage.⁽³⁾  

Study Participants

The primary study population was female caregivers with children under three years of age.  

Sampling Technique

For the survey, a two-stage stratified sampling approach was utilized within RpCC. In the first stage, each of the 33 wards were categorized into slum and non-slum areas based on their respective Mohallas (villages). Next, 48 Mohallas were selected, ensuring proportional representation of both slum and non-slum areas. In the second stage, a comprehensive list was compiled of households with children and women within the selected Mohallas to gather relevant information. Systematic random sampling was applied to enroll these households, aiming for proportional inclusion of children and women with disabilities, as well as those living in urban slums.  

For qualitative exploration in the RpCC field site, participants eligible for RI and TT vaccination were selected from the survey data based on the doses received (all, some, or none). At the Dhaka field site, convenience sampling was employed to select participants for focus group discussions (FGDs), key informant interviews (KIIs), and in-depth interviews (IDIs). The team coordinated with one of the largest specialized hospitals to identify individuals with comorbidities and healthcare workers. With the assistance of hospital authorities, patients with cardiac issues and healthcare workers were selected for interviews. 

Data Collection Tools

The WHO’s BeSD survey tool was adapted for RI and TT vaccines to determine uptake and adapted to collect information from both documented records and oral reports. To explore the enablers and barriers to vaccine acceptance, a combination of BeSD qualitative interview guides were used for IDIs, FGDs, and KIIs.  

Study Procedures 

The survey was deployed in the RpCC field site between October and November 2023. Caregivers of eligible children (0–3 years of age) were recruited as survey respondents for both RI and TT. Participants who had received at least one vaccine were asked to present their vaccine card to determine the proportion of participants who had their vaccine card. Both documented records and oral accounts were used to verify a child’s vaccination status using the adapted BeSD survey tool. Unvaccinated cases were identified if there was no vaccination reported, no documented history, and no BCG scar visible by six weeks of age. For the purposes of this study, zero-dose children were defined as children who missed the first dose of pentavalent vaccine by six weeks of age. According to the government’s schedule for TT vaccination, women of reproductive age are expected to receive five doses and vaccine uptake was assessed accordingly using the adapted BeSD survey tool.  

The qualitative assessment of enablers and barriers to vaccine acceptance was conducted in two study sites in Rangpur between January and February 2024, and in Dhaka from April to August 2024. After seeking informed written consent, IDIs, KIIs and FGDs were conducted with participants across the three study sites and recorded using audio-recorders.  

Analysis

To analyze the quantitative data, descriptive statistics were performed to summarize demographic characteristics and vaccine uptake status. Additionally, inferential statistics were conducted to examine associations between vaccine uptake and basic demographic information and estimate the prevalence of zero-dose children for RIs and TT vaccine. STATA 15 software was utilized for data analysis. 

IDI, KII and FGD recordings were transcribed verbatim and compiled in Microsoft Excel for electronic record-keeping. A BeSD framework matrix analysis was conducted to analyze the qualitative data, using data coding and matrix analysis. The list of themes was shared, reviewed, and discussed to reach a consensus. Any new information that did not align with existing themes was defined and categorized through discussions between the research team. Microsoft Excel software was used for analysis. 

Quantitative Findings 

Demogrphic Characteristics and Vaccine Status

The study enrolled 1510 female caregivers of children aged 3 years and under (609 to assess RI uptake

and 901 to assess TT uptake). Most women were aged 21–0 years. The predominant occupation was housewife, representing 97% of females in the RI group and 95% in the TT group. Education levels were similar between the RI and TT group, with over half in each group (RI: 53%, TT: 52%) having completed up to secondary education. In the RI group, 98% (598/609) had one child under 3 years old, with 51% (309/609) of these children being female. Disabilities were reported in only 0.66% (4/609) of children in the RI group and in 0.33% (3/901) of women in the TT group.  

Regarding vaccine uptake, 51.4% (313/609) of children in the RI group received all vaccines according to their age and schedule, while 67% (604/901) in the TT group received all doses. RI was rated as highly important by 97% (592/609) of respondents, and the TT vaccine was similarly rated as highly important by 92.79% (836/901) of participants. Both groups showed high trust in healthcare workers, with 94% (575/609) of the RI group and 93% (839/901) of the TT group expressing strong trust. 

Vaccine Card

Among participants who had received at least once vaccine, 95% (574/605) confirmed that they received a vaccine card for their child, with a similar rate for TT vaccines at 95% (844/886). When asked to show the vaccine card, 84% (511/605) of respondents were able to present the card for RI, while only 23% (210/886) could present it for TT vaccination. Regarding reasons for being unable to show the card, 14% (13/94) of caregivers reported losing their child’s vaccination card, and 61% (514/886) reported losing their own TT card. 

Routine Immunization

Figure 1 shows the RI status of the children in RpCC, based on data from vaccine cards (n=511) and oral accounts (n=94). Approximately 2% (11/609) of surveyed children had missed the BCG vaccine. No vaccination was reported for 4 children.  

Figure 1. Vaccination status of children under 3 years of age in RpCC 

Zero-Dose

Among the enrolled children, approximately 4% (22/609) were classified as zero-dose. A bivariate analysis revealed that caregiver occupation (P=0.01) and number of children (P<0.001) were associated with zero-dose children.  

BeSD Analysis of RI

The BeSD analysis identified that 85% of respondents (517/609) felt encouraged by religious leaders to vaccinate their children, and 87% believed local influential persons motivated vaccination efforts. Healthcare workers also played an important role, with 82% of respondents receiving recommendations from healthcare workers for child immunization. However, some challenges emerged: 5% of mothers (32/609) needed permission from household heads/senior members to proceed with vaccinations. A further 4% (24/609) were turned away from the vaccine centers, and 22% (132/609) incurred out-of-pocket costs for transportation purposes and to receive a photocopy of the vaccine card. Additionally, 20% (123/609) were not informed properly about vaccine availability in the area for their children. 

TT Vaccine for Women Aged 15–49 years

Approximately 66% (595/901) of women completed all required TT doses within the specified age group. A bivariate analysis of those who received all vaccine doses and those who did not found an association with age (P<0.00), occupation (p=0.07) and education (p=0.03).   

BeSD Analysis of TT Vaccine

The BeSD analysis of key social and behavioral factors affecting TT vaccination uptake among women revealed that 96% (862/901) believe they have support from family and friends for getting the vaccine, while 79% (714/901) feel encouraged by religious leaders. Additionally, 85% of community leaders and 82% of healthcare workers expressed support for TT vaccination. However, only 49% (440/901) of respondents received reminders for their TT dose, and 17.2% sought permission to get vaccinated. While 99% know where to access the TT vaccine, 23% reported being unaware of its availability in their area. Out-of-pocket expenses for obtaining the vaccine were reported by 13% of respondents.  

Qualitative Findings 

In total, 83 IDIs, 5 FGDs, and 10 KIIs were conducted across the three study sites. Specifically, 40 qualitative interviews were conducted in RpCC (3 FGDs, 6 KIIs, and 31 IDIs) and 43 qualitative interviews were conducted in Dhaka (2 FGDs, 4 KIIs, and 37 IDIs). Findings for RI and TT vaccine are summarized in Tables 1 and 2.  

Table 1. BeSD findings, RI for children 

Table 2. BeSD findings, TT vaccine for women aged 15–49 years 

Table 3. BeSD findings, COVID-19 vaccine for priority risk groups 

Recommendations for RI and TT programs  

Suggestions for the Adoption COVID-19 Vaccines in the National Immunization Program

• Prioritize vaccination of vulnerable groups based on exposure risk, rather than by age or status (e.g., healthcare workers, the elderly, or pregnant women) 

• Promote vaccination efforts from the grassroot level and consider increased participation of non-governmental organizations to effectively distribute vaccines 

• Make COVID-19 vaccines accessible at antenatal care centers, potentially integrated with RI 

• Consider integrating COVID-19 vaccines in the EPI for babies to help alleviate parental concerns around COVID-19 vaccination  

• Advocate for door-to-door vaccination efforts, supported by legislation, and set up local vaccination camps to broaden access to vaccination and facilitate the dissemination of information 

Overall Recommendations for Policy, Programming, and Practice 

• Increasing the number of female vaccinators, along with providing mobile toilets and privacy curtains at vaccination centers, can enhance comfort for women, encouraging them to accept vaccines for themselves and their children.  

• In addition to nationally adopted strategies, higher authorities should prioritize culturally appropriate approaches to improve vaccine coverage in diverse communities.  

Conclusions 

Through applying the BeSD framework, the study provided detailed insights into the factors affecting vaccine uptake and acceptance amongst zero-dose children and women in Bangladesh. Key findings included that although many caregivers were aware of the benefits of vaccination, the study identified gaps in knowledge, alongside fears and skepticism, influenced by community beliefs and personal experiences. Health workers, religious leaders, family and friends, and local influential persons were found to play an important role in motivating people to receive immunizations. However, several practical factors affected vaccine uptake, including out-of-pocket costs, difficulty travelling to the vaccination site, overcrowding, a lack of information about vaccine availability, and inadequate staffing and facilities. The insights informed the development of tailored recommendations to address the existing barriers and challenges and improve vaccine uptake among zero-dose children and women in Bangladesh.  

References 

1. World Health Organization. COVID-19 pandemic fuels largest continued backslide in vaccinations in three decades 2022 [Available from: https://www.who.int/news/item/15-07-2022-covid-19-pandemic-fuels-largest-continued-backslide-in-vaccinations-in-three-decades.
2. World Health Organization. Diphtheria tetanus toxoid and pertussis (DTP) vaccination coverage 2024 [Available from: https://immunizationdata.who.int/global/wiise-detail-page/diphtheria-tetanus-toxoid-and-pertussis-(dtp)-vaccination-coverage?CODE=ETH&ANTIGEN=DTPCV1&YEAR=.
3. UNICEF. Leaving No Child Behind: Scaling up investment in immunization to protect against diseases 2021 [Available from: https://www.unicef.org/bangladesh/media/5271/file/Immunization%20Advocacy%20Brief%20final.pdf.pdf. 
4. World Health Organization. Behavioural and social drivers of vaccination: tools and practical guidance for achieving high uptake 2022 [Available from: https://www.who.int/publications/i/item/9789240049680.