Disparities and barriers to life-course vaccination in Ethiopia: Evidence from a household survey

ABSTRACT

Achieving equitable access to life-course vaccination is a central objective of the global Immunization Agenda 2030 (IA2030). Ethiopia has made notable gains in routine immunization; however, disparities remain, particularly in underserved, pastoralist, and conflict-affected regions. This study assessed vaccination coverage, disparities, and barriers to service utilization across four regions of Ethiopia. A community-based cross-sectional survey was conducted in 57 woredas (districts) of Afar, Amhara, Oromia, and Tigray Regional states. Trained health workers administered digital questionnaires with GPS-enabled devices to caregivers, and eligible individuals subsequently received vaccines. The study enumerated 1.2 million households comprising 5.3 million individuals, including children under five, adolescent girls (9–14 y), pregnant women, and person aged 12 y and above. Descriptive and geospatial analyses were applied to examine coverage levels and disparities. The findings were revealed that 9.1% were zero dose, and 11.2% under-immunized, with measles-containing vaccine (MCV1) coverage at 88.3% among children aged 12–59 months. In addition, 79.6% of pregnant women were received tetanus-diphtheria (Td) vaccine, 75.3% of adolescent girls received Human Papilloma Virus (HPV) vaccine, while only almost half 53.8% of individuals aged 12 y and above received COVID-19 vaccine. Marked regional disparities were emerged: Afar recorded the highest zero-dose prevalence (24%), whereas Amhara and Tigray reported disparity levels below 10%. Despite progress in routine immunization, inequities persist, disproportionately affecting remote and marginalized populations. Addressing these gaps requires integrating geospatial microplanning, expanding mobile outreach, and applying culturally tailored demand-generation strategies to ensure equitable vaccine access and advance IA2030 targets.

Introduction

Vaccination remains one of the powerful tools in global health, preventing estimated 4–5 million deaths each year from vaccine-preventable diseases, such as measles, pertussis, polio, pneumonia, rotavirus diarrhea, and tetanus.^1,2 Yet, persistent inequities continue to leave millions unprotected. In 2022, approximately 20 million children worldwide did not receive the diphtheria-pertussis-tetanus (DPT) vaccine, classifying them as “zero-dose” children.^2,3 These children are disproportionately concentrated in fragile, conflict-affected, and geographically isolated regions, reflecting overlapping vulnerabilities tied to poverty, socioeconomic exclusions, and weak health systems.^3–5 Recognizing these challenges, public health experts and global partners have underscored the need for innovative solutions and coordinated action to ensure that everyone, everywhere, and at every age can benefit from vaccines.^6,7 This vision is embodied in the Immunization Agenda 2030 (IA2030), which seeks to close coverage gaps by prioritizing equity and targeting populations historically excluded from immunization services. However, progress toward universal immunization coverage is hindered by complex barriers including weak partnerships, lack of evidence-based, and data-driven decision making, geographic inaccessibility or health services, socioeconomic marginalization, and behavioral hesitancy.^8–10 In low-resource settings, travel distances greater than 5 km reduce vaccination uptake by 25–40%,^11,12 while conflict disrupt cold chain systems and service delivery.¹³ Remote communities in sub-Saharan Africa face compounded disadvantages, with zero-dose prevalence rates three to seven times higher than national averages.^14,15 These disparities were further intensified during the COVID-19 pandemic, which reversed nearly a decade of progress. Between 2019 and 2021, global coverage of the third dose of diphtheria-pertussis-tetanus vaccine (DTP3) declined from 86% to 81%, leaving 25 million children under immunized and unvaccinated.^16,17

Behavioral barriers represent significant obstacles to the effective delivery of vaccination services. These challenges are rooted in individual and community beliefs, attitudes, and decision-making processes, and arise from an interconnected web of factors. Vaccine hesitancy, often driven by safety concerns, misinformation, and institutional distrust, remain a central issue. For newer vaccines such as HPV, cultural norms and gender-specific delivery challenges create additional hurdles. School-based immunization programs, for example, fail to reach 30–50% of out-of-school girls in low-income countries.^18,19 Similarly, coverage of maternal tetanus-diphtheria (Td) vaccination remains suboptimal in settings where access to and utilization of antenatal care is limited.^20,21 These patterns highlight systemic weaknesses in reaching marginalized groups, including mobile populations, urban slum dwellers and other underserved communities, underscoring the need for tailored strategies that address both structural and behavioral determinants of vaccine uptake.^22,23

Ethiopia faces a substantial burden of zero-dose children. in 2019, 46.5% of children aged 12–35 months were unvaccinated. More recently, the WHO’s “Big Catch-Up” initiative reached nearly 959,000 zero-dose children, increasing coverage from 16% to 24% by mid-2025. Vaccination rates vary sharply across regions. Coverage is significantly higher in agrarian and urban areas (86–89%) compared to pastoral and rural regions, where coverage can be as low as 22% and zero-dose prevalence reaches 69%.²⁶ Nationally, Pentavalent (diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b (Hib) third dose coverage averages 61%, but disparities remain stark 83% in Addis Ababa versus only 19% in the Somali region.^24,25 Ethiopia introduced HPV vaccination services in 2018, achieving 91% coverage for the first dose in 2019. However, uptake declined, with only 74% of eligible adolescents vaccinated in 2022. Maternal immunization also remains inadequate: in the same year, less than half (42.4%) of pregnant mothers received tetanus – diphtheria (Td) vaccination. Most studies continue to focus narrowly on childhood vaccines, overlooking immunization needs across the life-course. This gap hampers the development of comprehensive and equitable immunization strategies that address adolescents, adults, and marginalized populations nationwide.^26,27

The convergence of these challenges underscores the need for integrated strategies to improve immunization coverage. Areas with a high spatial concentration of zero-dose children face 3.5-times higher mortality risks compared to areas with lower prevalence, often overlapping with conditions of malnutrition and poverty.^28,29 Emerging tools and approaches are helping to close these gaps. Geospatial technologies such as GPS mapping, enable precise identification and targeting of high-risk clusters.^30,31 At the same time, behavioral insights inform context-specific communication strategies that address hesitancy and build trust within communities while behavioral insights inform context-specific communication strategies.^32,33 Recent initiatives, including the “Big Catch-Up” campaign, highlight the importance of evidence-based and data-driven decision making. By combining geospatial microplanning with community engagement, these programs aim to overcome both supply-side and demand-side barriers, ensuring that immunization services reach the most vulnerable population.^34,35

This study responds to the recommendations of the 2023 Global Vaccine and Immunization Research Forum (GVIRF), which emphasized advancing innovations and opportunities in vaccines and immunization services.^36,37 Specifically, it examines the prevalence of zero dose children in targeted communities, assesses spatial accessibility to vaccination service and explores behavioral obstacles across life-course vaccination including routine childhood vaccines, COVID-19, HPV, and Td in four regional states of Ethiopia.^38–40 This study aims to provide comprehensive analysis of vaccination coverage, disparities, and barriers of immunization services in Ethiopia. Household clusters were mapped to the nearest health facility to evaluate geographic accessibility. The findings generate evidence-based, data-driven insights to strengthen planning and implementation of immunization services. By addressing both structural and behavioral barriers, the study contributes directly to achieving the equity commitments of the Immunization Agenda 2030 (IA2030).^41,42 This study contributes to the immunization literature by combining census-scale enumeration, geospatial accessibility analysis, and behavioral barriers assessment across the life course in equity-priority settings. Unlike nationally representative surveys, it provides granular, actionable evidence for microplanning and program optimization in underserved contexts.

Materials and methods

Study design and setting

A community-based cross-sectional study was conducted to assess life-course vaccination coverage, and describe disparities, and barriers of immunization services in four regions of Ethiopia. Afar, Amhara, Oromia, and Tigray – selected to represent diverse geographic, conflict-affected, socio-economic, and demographic contexts. Ethiopia is a federal democratic government established by 12 regional states and two city administrations. This structure is further divided into Zone administration, Woreda/District and Kebele/Village structure. Woredas serve as district-level units managing local government functions, such as health, education, and agriculture, while kebeles or villages represent the smallest administrative units, functioning as wards in urban areas or villages in rural settings where services are closest to households.

A structured house-to-house survey was implemented as a complete census of all household members across 57 woredas (10 in Afar, 15 in Amhara, 15 in Oromia, and 17 in Tigray), designed to capture variability in health infrastructure and immunization program coverage, with Figure 1 illustrating the geographical distribution of the study sites. The study targeted the Afar, Amhara, Oromia, and Tigray regional states, selected to ensure representation of diverse contexts, including geographic variation, conflict-affected settings, and differing socio-economic and demographic characteristics.

Figure 1.

Spatial mapping of the study area, 2025, Ethiopia.

Household data collection was conducted by Amref Health Africa, in collaboration with the Ministry of Health, as part of the Saving Lives and Livelihoods (SLL) project. The SLL project supports the integration of adult vaccination into routine immunization services using a life-course approach, including HPV, Td, and COVID-19 vaccines. As a reference, Table 1 presents the Ethiopian national routine immunization (RI) schedule alongside catch-up vaccination schedules, which guided the study’s assessment of coverage and service delivery.

Table 1.

Ethiopian routine and catch-up immunizations schedule, 2025, Ethiopia.

Vaccine	RI Schedule	Dosage	# of doses for RI	Route of Administration	Site of Administration	Consideration
BCG	At birth	0.05ml	1 dose	Intra-muscular	Right deltoid muscle of the upper arm	Up to one year of age
OPV	At birth, 6th, 10th, and 14th week	2 drops	4 doses	Oral	Oral administration	For a child miss normal schedule…
HepB–BD	At birth	0.5 ml	1 dose	Intra-muscular	Anterolateral side of the left mid-thigh	At birth or within 24 hours (up to 14 d for late doses)
Pentavalent	6th, 10th, and 14th week	0.5ml	3 doses	Intra-muscular	Antero-lateral side of the left mid-thigh	For a child miss normal schedule…
PCV	6th, 10th, and 14th week	0.5ml	3 doses	Intra-muscular	Antero-lateral side of the right mid-thigh	Provide 1st dose at first visit…
Rota	6th, 10th, and 14th week	2ml	3 doses	Oral	Oral	—
IPV	At 14th week and 9 months	0.5ml	2 doses	Intra-muscular	Right mid-thigh (2.5 cm apart from the PCV injection site)	—
MCV	MCV1 at age of 9 months and MCV2 at age of 15 months	0.5ml	2 doses	Subcutaneous	Left deltoid muscle of the upper arm	MCV1 can be given from 9–23 months…
Malaria vaccine	At 6th, 7th, 9th and 15th months	0.5ml	4 doses	Intra-muscular	Anterolateral side of left mid-thigh	—
Yellow Fever	At 9 months	0.5ml	1 dose	Intra-muscular	Right deltoid muscle of the upper arm	The vaccine can be given under one year
HPV	9 y old girls	0.5ml	1 dose	Intra-muscular	Left deltoid muscle of the upper arm	—
Td	Td1: At first contact…	0.5ml	5 doses	Intra-muscular	Left deltoid muscle of the upper arm	—
COVID-19 (Pfizer)	≥12 y	0.3ml	1 dose	Intramuscular	Left deltoid muscle of the upper arm	—
National catch-up vaccination schedule
Vaccine	Catch-up vaccination schedule	Dosage	Number of doses for catch up	Route of Administration	Site of Administration
OPV	12 to 59 months	2 drops	3 doses	Oral	Oral
Rota	12 to 24 months	2ml	3 doses	Oral	Oral
PCV	12 to 24 months	0.5ml	3 doses	Intra-muscular	Antero-lateral side of right mid-thigh
Pentavalent	12 to 24 months	0.5ml	3 doses	Intra-muscular	Antero-lateral side of left mid-thigh
IPV	12 to 24 months	0.5ml	2 doses	Intra-muscular	Right (outer) mid-thigh (2.5 cm apart from PCV injection site)
MCV	MCV1 for age 12–59 months, MCV2 for age 24–59 months	0.5ml	2 doses	Sub-cutaneous	Left deltoid muscle of the upper arm

Population and sampling strategy

The target population comprised all individuals residing in the 57 selected woredas. A complete enumeration of household members was undertaken to maximize inclusivity and minimize selection bias. Emphasis was placed on key demographic groups relevant to immunization equity and life-course analysis: children under 5 y of age, pregnant women, adolescent girls aged 9–14 y, individuals aged 12 y and above.

The study employed a purposive sampling technique to identify districts (woredas) most relevant to the objectives of assessing immunization equity. Districts were selected based on equity-focused criteria to ensure representation of populations at heightened risk of immunization inequities. Specifically, selection criteria included (i) high zero-dose burden, (ii) conflict-affected and post-conflict settings, (iii) hard-to-reach and marginalized communities, and (iv) inclusion of Gavi non – full portfolio districts. This sampling approach was designed to capture diverse contextual realities and ensure equitable representation across settings, thereby strengthening the validity of findings related to vaccination coverage, disparities, and barriers. Given the purposive, equity-focused selection of woredas, the findings of this study are intended to inform immunization strategies in high-risk and underserved settings rather than to provide nationally representative estimates. The analysis emphasizes programmatic learning and equity-oriented decision-making for priority populations, rather than population-level inference.

Data collection tools and procedures

Data were collected using a structured electronic questionnaire administered on tablet devices equipped with GPS facilities. The instruments were developed in line with Federal Ministry of (MoH) guidelines for standardized immunization surveys and carefully adapted to the local context.^25,26 Prior to data collection, comprehensive orientation sessions on the tools and ethical principles were conducted for data collectors, vaccinators, and supervisors. A five-day training program included pilot testing in areas outside the main study sites, enabling the research team to identify and address limitations before full implementation. Ultimately, data collection was conducted by more than 1500 trained health workers between April to June 2025. Information was obtained through in-depth interviews with mothers or caregivers. Vaccination status for all household members was verified using vaccination cards when available or caregiver self-reported otherwise.

Variables and operational definitions

The study assessed multiple variables, including geographic location, GPS distance to the nearest health facility, household size, composition, age, life course immunization status on COVID-19 vaccination uptake of eligible adults. Vaccination status was documented for key antigens: Pentavalent vaccines (Penta1 &3), measlescontaining vaccines (MCV1 and MCV2), COVID-19 vaccine, maternal tetanusdiphtheria (Td) vaccine for pregnant women, and HPV vaccine for girls aged 9–14 y.

In line with Gavi’s operational definitions, zero-dose children were defined as children aged between 12 and 23 months who had not received the first dose of a diphtheria, tetanus, and pertussis-containing vaccine (DTP1) by their first birthday. Correspondingly, under-vaccinated children were defined as those who had received DPT1 but not the third dose (DPT3) by the end of their first year. In this study, pentavalent vaccine doses (Penta1 and Penta3) were used as proxies for DTP1 and DTP3 coverage, respectively, since Ethiopia’s immunization program administers pentavalent vaccine in three doses before 5 y of age. In this study, pentavalent vaccine doses (Penta1 and Penta3) were used as proxies for DTP1 and DTP3 coverage, respectively, since Ethiopia’s immunization program administers the pentavalent vaccine in three doses before 5 y of age. This approach enabled identification of zerodose children (no Penta1) and undervaccinated children (received Penta1 but missed Penta3), in alignment with global immunization coverage monitoring standards.

Data management analysis

Data quality assurance

In this study, rigorous data quality assurance measures were implemented throughout the data collection and management process including GPS coordinators, which facilitated precise spatial data capture and helped to verify 10% of enumerations by supervisors and geographic accuracy of household locations relative to health facilities. Daily data quality monitoring was an integral part of the quality assurance framework. At central (server) levels, continuous oversight was maintained to promptly identify and address any emerging data issues. Feedback loops were established whereby supervisors and data collectors received on daily bases during data entries and reviews. These feedback sessions ensured that errors or inconsistencies were corrected in a timely manner, preventing the accumulation of flawed data.

A structured daily data review meeting was held at woreda and kebele levels by census supervisors in four regions. These meetings served as a platform to discuss data quality challenges, operational challenges, and take corrective actions.

Data analysis

Statistical analyses was conducted using Python, a versatile programming language well-suited for handling large datasets and complex computations. Descriptive statistics were primarily employed to summarize key demographic characteristics and vaccination coverage using frequencies, and percentages, providing a comprehensive overview of the population and immunization status. Spatial analyses were used to delineate the study area for vaccination coverage. Using GPS data, straight-line (Euclidean) distances from households to the nearest health facility were calculated to quantify physical accessibility. Spatial data processing and mapping were performed using GeoPandas, with Matplotlib and Seaborn utilized for data visualization. Euclidean distance was used as a pragmatic proxy for physical accessibility due to the absence of complete and reliable road network data across conflict-affected and pastoralist areas. While this approach may underestimate true travel time, particularly in mountainous or mobile pastoralist settings – it allows for consistent comparison across regions. The analysis therefore emphasizes relative spatial patterns rather than absolute travel burden. Households without GPS coordinates were excluded from spatial clustering analyses but retained in descriptive coverage analyses to minimize data loss.

The results were presented using descriptive statistics to fully characterize vaccination coverage, disparities and barriers of utilization of immunization services.

Heatmap classification and performance thresholds

Heatmaps were used to visually summarize vaccination coverage, zero-dose prevalence, under-immunization, and dropout rates across woredas. Performance categories were defined using standardized programmatic thresholds. For vaccination coverage indicators (MCV1, MCV2, HPV, Td, and COVID-19 first dose), green shading indicated strong program performance (≥90%), yellow indicated moderate performance requiring monitoring (75.0–89.9%), and red indicated low performance requiring urgent intervention (<75%).

For zero-dose and under-immunized children, green indicated strong performance (<5.0%), yellow indicated moderate concern (6.0–20.0%), and red indicated high concern (>20.0%). For pentavalent vaccine dropout rates, green represented dropout ≤5.0%, yellow 5.1–10.0%, and red >10.0%. These thresholds were applied consistently across all scorecards and tables.

Ethical considerations

The study was conducted in accordance with the principles of the Declaration of Helsinki and received approval from the Institutional Review Ethics Committee of the Federal Ministry of Health (protocol code: ETCO/Admin/550/25, approval date: April 1, 2025). Informed consent was obtained from all participants. For children under 15 y of age, consent was obtained from their caregivers. Participants were fully informed about the study’s objectives, procedures, data handling practices, and their rights, including voluntary participation and the option to withdraw at any time. Data collectors received training on ethical research conduct, with emphasis on safeguarding participant privacy and appropriately managing sensitive topics related to gender and health behaviors. To ensure confidentiality, data were anonymized and geospatial identifiers were aggregated. This approach guaranteed that every household present during field visits and providing informed consent was included in the study population. Furthermore, all eligible zerodose and underimmunized children identified during the survey were vaccinated with the appropriate antigens. Vaccination during survey visits followed national immunization guidelines and was implemented by certified vaccinators. Cold-chain integrity was ensured through the use of monitored vaccine carriers, and verbal informed consent was obtained prior to vaccination. Two delivery approaches were applied depending on context: in pastoralist and mobile communities, an “identify-and-vaccinate” approach was implemented during the same household visit; in more stable settings, eligible individuals and coverage gaps were first identified, context-specific micro-plan were developed, and nearby health facilities subsequently returned to deliver vaccination services

Results

Demographic characteristics

The data were collected in 15 urban and 42 rural woredas of four regional states in Ethiopia. While 10 (67.0%) of urban administrations were enrolled from the Amhara region, close to two -thirds of targeted rural woredas were in the Oromia and Tigray Regions. In all 57 woredas, 1.2 million households and 5.3 million people were enumerated. The average household size was 4.4 persons and the largest HH size was 5.3 persons found in Afar region. Within these households, there were 502,193 children under five of age, 312,019 girls aged 9–14 y old, 78,140 pregnant women and 2,518,976 adults aged greater or equal to 12 y. The demographic characteristics of the complete collected data set during household enumeration are provided in Table 2 below. GPS coordinates were successfully recorded for 70% of households, the remaining households have no GPS due to security issues.

Table 2.

Demographic characteristics of study population, June 2025, Ethiopia.

Region	Afar	%	Amhara	%	Oromia	%	Tigray	%	Total	%
Number of woredas	10	17.5%	15	26.3%	15	26.3%	17	29.8%	57	100%
Residence
Urban	4	26.7%	10	67.0%	0	0%	1	6.7%	15	100%
Rural	6	14.3%	5	11.9%	15	35.7%	16	38.1%	42	100%
Distance in Km from Health Facility
<5km	48,162	65.9%	397,480	85.5%	336,448	82.1%	159,964	60.8%	942,054	77.8%
5 - to 10 Kms	10,742	14.7%	45,878	9.9%	51,310	12.5%	61,780	23.5%	169,710	14.0%
>10 Kms	14,224	19.5%	21,603	4.6%	22,188	5.4%	41,343	15.7%	99,358	8.2%
total population	390736	7.3%	1773702	33.2%	2014375	37.7%	1161580	21.8%	5340393	100%
Number of households	73128	6.0%	464961	38.4%	409946	33.8%	263087	21.7%	1211122	100%
Number of HHs with GPS coordinates^	64,203	5.3%	252,694	20.9%	310,859	25.7%	219, 559	18.1%	847,315	70%
Household size	5.3	1.2	3.8	0.9	4.9	1.1	4.4	1.0	4.4
Number of children 12–59 months of age	53694	10.7%	156260	31.1%	148993	29.7%	143246	28.5%	502193	100%
Number of girls 9 to 14 y of age	41700	13.4%	68739	22.0%	130189	41.7%	71391	22.9%	312019	100%
Number of pregnant women	12381	15.8%	16554	21.2%	28447	36.4%	20758	26.6%	78140	100%
Number of adults age 12+ Years	147300	5.8%	975156	38.7%	812060	32.2%	584460	23.2%	2518976	100%

NB: ^GPS coordinates were not taken where active armed conflict happed in Amhara region.

Life-course vaccination coverage

The life-course vaccination coverage for this study addresses the proportion of a population that has received childhood immunization, HPV vaccine for girls aged nine to 14 y, Td vaccine for pregnant women and COVID-19 vaccine for adolescents and adults aged greater or equal to 12 y. The overall Penta 1, HPV, Td and COVID vaccine coverage were 90.9%, 75.3%, 79.6%, 53.8% among children 12-59 months, girls nine to 14 y, pregnant women and adolescent and adults aged greater or equal to 12 y, respectively. On one hand, the highest immunization rates of Penta1 vaccine were 94.2% and 93.9% in the Tigray and Amhara regions, and the lower and lowest Penta1 vaccine coverage were 88.7% and 75.8% in the Oromia and Afar regions, respectively. Similarly, most of children 12–59 months of age (92.6% and 92.9%) took the third dose of Penta3 vaccine in the Tigray and Amhara regions, while only 86.2% and 73.7% of children 12–59 months of age took Penta-3 vaccines in the Oromia and Afar regions, respectively. Furthermore, the highest Measles Containing Vaccine (MCV1) service coverage was 87.9% and 84.3% for children 12–59 months of age in the Amhara and Tigray regions, which were followed by 79.4% and 67.5% in the Oromia and Afar regions, respectively (Figure 2). The highest Td vaccine coverage was 86.9% vaccinated among pregnant women in the Amhara region, while the lowest was 62.3% in the Tigray region. In addition, the highest (88.9%) received HPV vaccine coverage among girls aged nine to14 y was in the Amhara region, while the lowest (61.4%) percentage of girls were vaccinated in the Afar region. Furthermore, the highest COVID vaccine coverage was observed in Tigray at 57.8%, followed by 53.9% in the Amhara and 53.5% in the Oromia regions. Afar had the lowest COVID vaccine uptake at just 42.1%.

Figure 2.

Antigen coverage by region and age group, June 2025, Ethiopia.

COVID vaccine coverage among high-risk population groups

Among people enumerated who were eligible for COVID-19, 53.8% were vaccinated with at least one dose. Of those aged greater than 60 y, 95.6% and 59.6% of eligible people were vaccinated in the urban and rural area of the Tigray region respectively. In addition, out of immune- compromised people, the least COVID-19 vaccination coverage was 46.5% in the urban area of Afar region. Furthermore, among pregnant women, the least COVID-19 vaccine coverage was 26.4% in the Amhara rural area. Table 3. Presents the COVID-19 vaccine coverage among high-risk population groups.

Table 3.

COVID-19 vaccine coverage among high-risk population groups, June 2025, Ethiopia.

NB: Heatmap color classifications are defined in the Methods section (Heatmap Classification and Performance Thresholds).

Life-course vaccination scorecard

Based on the WHO and MOH recommendations, a life-course vaccination scorecard was developed in this study as a tool to track and monitor immunization programs across all age groups – from childhood through old age. In the dashboard, each woreda’s relative immunization coverage score is displayed using green, yellow, and red labels, ranging from highest to lowest performance. Conversely, the proportions of missed vaccinations are presented in reverse order, with red, yellow, and green labels indicating the highest to the lowest levels of missed doses, respectively.

The life-course vaccination proportion of zero dose, under immunized, MVC, HPV, Td and COVID-19 are presented using a scorecard for 42 rural woredas in four regional states of Ethiopia. The majority of highest proportion of zero dose children depicted in the dashboard was among woredas in the Afar region, followed by woredas in the Oromia region. Bure Medaytu woreda reported slightly higher than half (54.5%) zero dose (57.7%) under immunized eligible children who missed vaccination services recommended for their age. Similarly, less than half (42.4% and 48.3%) were vaccinated for MCV1 and Td+ among eligible children and pregnant women. Furthermore, only one-fourth (26.4%) of adolescents and adults aged greater or equal to 12 y were vaccinated for the first dose of the COVID-19 vaccine. The highest vaccination service performances were reported from the Amhara and Tigray regions, which are labeled in green in the scorecard below (see Table 4).

Table 4.

Life-course vaccination service coverage disparities in 42 rural woredas across four regional states in Ethiopia, June 2025 – with cell shading to illustrate performance (red = higher zero dose, green = higher coverage).

NB: Heatmap color classifications are defined in the Methods section (Heatmap Classification and Performance Thresholds).

The life-course vaccination proportion of zero dose, under immunized, MVC, HPV, Td and COVID is presented using a scorecard for 15 urban woredas in three regional states of Ethiopia. Although the immunization coverage in urban areas showed the highest in the most censused town administration, pastoralist areas were highlighted in orange and red in the scorecard for lowest immunization performance when compared with agrarian town administrations. Awash town was reported 20.3%, 20.9% 78.7%, 63.9% and 39.1% for zero dose, under immunized, MCV1 and COVID-19 first dose, respectively. In addition, Semera Logia town vaccinated only 42.9% of girls age nine to 14 and adolescents and 11.3% of adults greater or equal to 12 y eligible for HPV and COVID-19 vaccine (Table 5). The dashboard depicted the existing regional disparities in vaccination service utilization.

Table 5.

Life-course vaccination service coverage disparities in 15 urban woredas in three regional states in Ethiopia, June 2025, Ethiopia.

NB: Heatmap color classifications are defined in the Methods section (Heatmap Classification and Performance Thresholds).

Spatial distribution of zero-dose children

Among the total 1,211,122 households, 847,315 (69.9%) households have valid GPS coordinates across the four regions of Afar, Amhara, Oromia, and Tigray. The majority of the GPS missed were in the Amahra region due to the current conflicts. Of those households that had valid GPS, 9.1% were found to contain at least one child aged 12–59 months who had not received the first dose of the Penta1 vaccine. The spatial analysis revealed substantial heterogeneity in the distribution of zero-dose households across the regions. Geographic clusters with disproportionately high concentrations of zero-dose children were identified, particularly in the Afar Region. Figure 3 shows a distribution of a 95%ile reported zero dose children by woreda in four regional states of Ethiopia (Figure 3).

Figure 3.

Spatial mapping of the zero dose children (12–59 months of age), June 2025, Ethiopia.

Geographic access to static health facilities

Figure 4 below presents the proportion of children who missed both Penta1 and Penta3 by distance for static health facilities. In all settings, the largest percentage ranging from 53% to 87% missed opportunities were reported by communities residing within a five km radius of the nearest health facility. A significant proportion ranging from 14% to 33% of communities who missed vaccination services reside within a 10 km radius to the static health facility in pastoralist and agrarian settings (Figure 4).

Figure 4.

Proportion of missed vaccination opportunities by distance from static health facility in urban, pastoralist and agrarian settings, June 2025, Ethiopia.

Reasons for non-vaccination in under five children

Figure 5 shows the main reported barriers to child immunization, measured by the number of unvaccinated children. The most common reason was lack of information on appointment dates (26.3%), followed by long distance to the immunization site (17.8%), and inappropriate timing (13.8%). Other barriers included fear of vaccine side effects, lack of information, session interruptions, household responsibilities, and other factors, with the latter being the least reported (1%) (Figure 5).

Figure 5.

Reason for under 5 children non-vaccination June 2025, Ethiopia.

Discussion

The result of this large-scale study conducted in four regional states of Ethiopia provides evidence and data for decision making in developing a “Big Catch up”¹⁶ and “recovery” vaccination plan in conflict affected areas aiming to improve disease prevention and health promotion throughout the population’s life course. The highest number of zero-dose and under immunized children were identified in rural and pastoralist woredas. In addition, a significant number of girls and adults missed HPV and COVID-19 vaccines in all regions, respectively. The findings of this study contribute in the identification of high-risk populations groups and its magnitude in different context in Ethiopia.^16,31

Our findings underscore persistent and complex disparities in immunization coverage across different population groups and life stages in Ethiopia. While geographic inaccessibility and health infrastructure limitations have often been cited as key barriers to immunization, our data suggest a more nuanced picture. Notably, over half of zero-dose and under-immunized children reside within a five-kilometer radius of a fixed health facility, indicating that proximity to services alone does not guarantee uptake. This finding diverges from patterns observed in Kenya, Somalia, and Nigeria, where the majority of missed children lived more than 10 km from a facility and where distance is a more dominant barrier to immunization uptake.^10,11,13 In the Ethiopian context, these results point toward a combination of individual, and system-related challenges such as fear of side effects, misinformation, low caregiver awareness, inappropriate schedule, short service hours, and session interruption due to mobility as critical mechanisms limiting vaccine demand and service utilization.²⁶ Compared with pastoralist settings in Kenya, Somalia, and northern Nigeria – where distance to facilities is the dominant barrier – our findings suggest that in Ethiopia, service reliability, trust, and scheduling constraints play a comparatively larger role, as most zero-dose children reside within 5 km of a health facility.

Beyond physical access, human and social factors substantially influence life-course vaccination uptake, particularly in pastoralist and underserved communities. Mobility linked to livelihoods, competing household priorities, and uncertainty around follow-up visits often lead to delayed or missed vaccinations, even when caregivers recognize their benefits. Gender dynamics also shape vaccination behaviors. While women are primarily responsible for child healthcare, decision-making authority and control over resources often lie with male household heads or elders, limiting timely uptake – especially for life-course vaccines such as HPV and COVID-19.¹⁷

The disparities between pastoralist and agrarian regions further reveal structural inequities embedded within the health system. In regions like Afar, one in every four children aged between 12 and 59 months were categorized under zero-dose while one in ten children were missed the first dose of Pentavalent vaccine 1 in Amhara and Tigray Regions.^36,38,39 These differences are not solely due to geographic barriers but also reflect deeper systemic issues including population mobility, low health system penetration, limited outreach infrastructure, and in some areas, the lingering effects of conflict and insecurity.^36,39,40 The findings resonate with global literature that has documented how fragile settings and mobile populations remain disproportionately affected by immunization gaps.^4,11,13,14 Similar to trends seen in other lower-middle-income countries, spatial clustering of zero-dose children often overlaps with social exclusion, poverty, and weak public services.^11,14,23 Advanced equity metrics have also revealed a high prevalence of zero-dose children among underserved and special populations.^25,39,40

The other disparities emerged in this study was on childhood vaccination coverage which was relatively high in some areas and antigens. But vaccination services coverage targeting adolescents and adults, such as HPV, tetanus-diphtheria (Td), and COVID-19 remain suboptimal. This finding was in line with previous studies conducted in some part of Ethiopia.^41,42 In addition, this finding was consistent with other study on HPV, and Td vaccination.^20,22 Furthermore, under-five vaccine hesitancy reflects broader concerns around trust, risk perception, and misinformation.^30–32

Beyond structural barriers, our findings highlight the important role of socio-cultural and gender-related factors in shaping life-course vaccination uptake, particularly for HPV, tetanus – diphtheria (Td), and COVID-19 vaccines. Vaccine decision-making in many Ethiopian settings is strongly influenced by household power dynamics, social norms, and trust in health systems, which extend beyond simple issues of service availability.¹⁷ Similar patterns have been documented in equity-focused immunization studies in Ethiopia and other low- and middle-income countries, where behavioral and social drivers significantly affect vaccine uptake among marginalized populations.^{8,29–32,39,40}

Gender norms play a central role in HPV vaccination among adolescent girls. Decisions regarding vaccination are often mediated by parents or male household heads, limiting autonomy for girls – particularly those who are out of school and therefore missed by school-based delivery platforms. Evidence from Ethiopia and comparable settings shows that out-of-school girls face systematic exclusion from HPV services, contributing to persistent coverage gaps.^17–19,41 These challenges underscore the need for alternative, community-based delivery strategies that extend beyond schools.

Trust in health services and religious or community authority also shapes vaccine acceptance, especially in pastoralist and underserved areas. Limited continuity of services, prior experiences of stock-outs or interrupted sessions, and reliance on informal information networks can reinforce hesitancy toward both routine and newer vaccines. Studies from Ethiopia highlight how low institutional trust and misinformation interact with cultural beliefs to influence immunization behaviors across the life course.^{8,17,30–32,41}

Mobility further compounds these socio-cultural barriers in pastoralist communities. Seasonal movement and livelihood priorities reduce opportunities to complete multi-dose schedules and weaken routine engagement with fixed health facilities. When combined with inconsistent outreach services, these factors contribute to lower uptake of Td, HPV, and COVID-19 vaccines, even in areas located relatively close to health facilities. Similar dynamics have been described in pastoralist and mobile populations elsewhere in sub-Saharan Africa.^22,36,39

Together, these findings suggest that improving life-course vaccination coverage requires strategies that go beyond physical access, integrating gender-responsive approaches, engagement with trusted community and religious leaders, and service delivery models adapted to mobile populations. Addressing these socio-cultural determinants is essential to achieving the equity goals of IA2030 and sustaining gains from initiatives such as the Big Catch-Up.^{16,31,34,35,41}

Coverage in pastoralist regions remains particularly low due to challenges like population mobility, geographic barriers, and limited health infrastructure. Nonetheless, targeted interventions such as mobile outreach strategies and strengthening static services in health centers and health posts have shown potential to improve access in these hard-to-reach communities.^36,39 To build on these efforts, immunization programs should expand microplanning and geospatial targeting to identify zero-dose and under-immunized clusters.^27,28 Additionally, increasing vaccine coverage among adolescents and women requires expanding delivery platforms beyond schools and health facilities. Community-based outreach integrated with maternal and adolescent health services is essential to reach marginalized and out-of-school populations.^20,22

The study revealed significant number of care takers and individuals with limited knowledge in favor of routine immunization services. The result concurs with reported barriers like social norms, low level of awareness on severity and susceptibility to vaccine preventable diseases, high level distrust on public services.^29,30,32 Hence, co-designing behavioral change communication materials and tool, and imbedding it within broader health promotion strategies were found fundamental to get a positive result.^29,30,32

Finally, this study highlights the value of data-driven decision making and informing Big Catch up and recovery plans within regular immunization systems. Although direct causal attribution cannot be established, observed improvements in national coverage indicators following the implementation of the Big Catch-Up initiative are consistent with intensified outreach and equity-focused strategies and generating actionable intervention at village health post level. This immunization service delivery model aligns with the IA2030 framework and Gavi’s “Big Catch-Up” strategy, both emphasizing the use of local data for equity-driven decision-making and program planning.^16,31,34,35

This study has several limitations. First, it was conducted in 4 of 12 regions and 57 of 1180 woredas, limiting generalizability. Second, key antigens such as BCG, OPV0, IPC, Rota 1–3, and yellow fever were not included. Third, findings reflect only the first phase of data collection; subsequent cyclic visits were planned but not yet completed. Finally, caregiver recall may have affected vaccination histories.

Beyond these general limitations, geographic access is a critical factor influencing immunization coverage. Access was measured using straight-line (Euclidean) distance and classified as good, moderate, or poor. Road-network distance or actual travel time was not used due to the lack of complete and reliable road and pathway data, particularly in remote, pastoralist, and conflict-affected areas. Euclidean distance may therefore underestimate true travel burden; however, the classification provides a valid measure of relative spatial access and supports identification of clusters of zero-dose and under-immunized children. Vaccine uptake also depends on program-delivered factors, including service availability and cold-chain reliability. Children living farther from facilities may be at higher risk of being zero-dose or under-immunized, while even those nearby may remain unvaccinated due to mobility, caregiver awareness, trust, or socio-cultural barriers. Distance classification reflects potential geographic accessibility and should be interpreted alongside these programmatic and social determinants.

Conclusions

While Ethiopia has made notable progress in childhood vaccination, inequities remain entrenched in life-course immunization, with pastoralist, remote, and underserved populations most affected. Coverage for HPV, tetanus – diphtheria, and COVID-19 lags behind, constrained by both access and behavioral barriers. Addressing these challenges requires integrated strategies, geospatial microplanning, mobile outreach, expanded delivery platforms, and culturally tailored communication. Embedding such innovations within Ethiopia’s primary health system is essential to achieving IA2030 equity goals. This study illustrates the potential of combining service delivery with large-scale data generation to inform policy and strengthen immunization systems in Ethiopia and beyond.

Biography

Geteneh Moges Assefa is a public health expert with more than 11 y of international experience in monitoring, evaluation, and research. He has authored nine publications focused on health and development and has collaborated with governments and NGOs throughout Eastern Africa. His areas of expertise include conducting impact evaluations, community-based research, and strengthening capacity building initiatives.

Funding Statement

This research was funded by master card foundation under the Saving Lives and Livelihoods (SLL) initiative, grant number R252 and The APC was funded by R252.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data presented in this study is available on request from the corresponding author due to privacy reasons.

Institutional review board statement

“The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board of Federal Ministry of Health (protocol code ETCO/Admin/550/25 and date of approval April 01, 2025).” for studies involving humans.

Informed consent statement

“Informed consent was obtained from all subjects involved in the study.”