Prevalence, geographical distribution and factors associated with pentavalent vaccine zero dose status among children in Sindh, Pakistan: analysis of data from the 2017 and 2018 birth cohorts enrolled in the provincial electronic immunisation registry

Prevalence, spatial variation and determinants of zero-dose children in Ethiopia: Spatial and multilevel analyses

OBJECTIVES

Vaccination is a crucial public health intervention protecting individuals and communities from vaccine-preventable diseases. However, unvaccinated children in low- and middle-income countries pose a significant challenge. Ethiopia, a Global Alliance for Vaccines and Immunisation (GAVI)-supported country, ranks fifth in zero-dose immunisation burden, indicating concerning vaccine coverage gaps. Despite the severity of this issue, there is a dearth of research investigating the disparities, prevalence and contributing factors associated with zero-dose children in Ethiopia. This study aimed to assess the prevalence, spatial distribution and determinants of zero-dose children in Ethiopia.

STUDY DESIGN

A community-based cross-sectional study was conducted using data from the 2019 Ethiopian Mini Demographic and Health Survey (EMDHS). Data were collected from 21 March 2019 to 28 June 2019.

METHODS

The study included a total of 1334 children aged 12-35 months (weighted sample). For spatial and multilevel analyses, ArcGIS 10.8 and Stata 17 software were used, respectively. The measure of association was determined by computing the adjusted odds ratio (AOR) at a 95 % confidence interval (95 % CI), and a p-value <0.05 was considered statistically significant.

RESULTS

The prevalence of zero-dose children in Ethiopia was 46.5 % (95 % CI: 43.8, 49.2). Southeast Amhara, Afar, Somali, Oromia and SNNPR (Southern Nations, Nationalities and Peoples' Region) regions had high zero-dose proportions. Maternal age 15-19 years (AOR = 1.63; 95 % CI: 1.05, 2.64), lack of antenatal care (AOR = 1.77; 95 % CI: 1.34, 2.35), rural residence (AOR = 1.94; 95 % CI: 1.17, 3.19) and region were significantly associated to zero-dose status in Ethiopia.

CONCLUSIONS

The prevalence of zero-dose children in Ethiopia was high and the distribution exhibited significant variation across the country's clusters. Individual and community factors were key contributors. It is essential that areas with a high prevalence of zero-dose children have access to recommended childhood vaccines. This proactive approach can help protect children from morbidity and mortality caused by vaccine-preventable diseases.

Evaluating an immunization carpool service for women in rural areas for facilitating routine childhood immunizations in Pakistan -a feasibility study on acceptability, demand, and implementation

Introduction

Poor accessibility of immunization services coupled with limited options for transportation and socio-cultural norms that hinder women's mobility are among the key factors contributing to poor immunization coverage in rural areas. We assessed the feasibility and acceptability of establishing a free-of-cost, women-only carpool service for immunization in a rural setting in Pakistan and evaluated its preliminary impact on immunization coverage and timeliness among children.

Methods

We conducted a feasibility study in four selected immunization facilities in Shikarpur District, Sindh. A local transport vehicle was hired and branded as an immunization carpool service. Women having un- or under-immunized children aged ≤2 years were invited to visit immunization facilities using carpool vehicles. Information on demographic indicators and service experience was collected. Child immunization details were extracted using the government's provincial electronic immunization registry to estimate immunization coverage and timeliness.

Results

Between January and October 2020, six immunization carpool vehicles provided uninterrupted service and transported 2422 women-child pairs, completing 4691 immunization visits. Majority of women reported that the carpool service improved accessibility (99.6%) by offering group travel (82.9%) and reducing their dependency on family members (93.4%). Preliminary estimates reported an increase in immunization coverage and timeliness across antigens among participating children compared to non-participating children, with significant increase in proportion for BCG coverage (38.1%; p < 0.001, CI: 32.8%, 43.4%) and measles-2 timeliness (18%; p < 0.001, CI: 13.3%, 22.4%).

Conclusion

A women-only immunization carpool service implemented within a rural setting is feasible and highly acceptable. Key factors contributing to the model's success include increased mobility and independence of women, cost-savings, and a culturally and contextually appropriate mechanism of transport embedded within the local setting. Increased accessibility to health services also contributed to improved immunization coverage and timeliness among children.

Patterns of basic pneumococcal conjugated vaccine coverage in Ethiopia from 2015 to 2018; further analysis of Ethiopian DHS (2016-2019)

Background

Geographic variation is crucial in spotting performance gaps in immunization programs, including the Pneumococcal Conjugated Vaccine (PCV). This will help speed up targeted vaccination and disease elimination programs in resource-limited countries. Thus, this study aimed to investigate the geographic variation and determinants of PCV vaccination coverage among children aged under five years old in Ethiopia.

Methods

This analysis was carried out based on the 2016 and 2019 nationally representative Ethiopia Demographic and Health Survey (EDHS). We included two surveys of 10,640 children aged 12-23 months. The spatial analysis also covered 645 and 305 clusters with geographical information for both 2016 and 2019, respectively. We explored the spatial distribution, global spatial autocorrelation, spatial interpolation, and Stats Can windows of children with PCV-3 vaccination. P-values were generated using 999 Monte Carlo simulations to identify statistically significant clusters. To understand the coverage of PCV-3 in all areas of the country, we employed the ordinary Kriging interpolation method to estimate the coverage in unsampled areas. We also used hierarchical multivariate logistic regression to identify the factors associated with the utilization of the PCV vaccine (full vaccination).

Results

Except for Addis Ababa, children in all regions have lower odds of receiving all three PCV vaccines compared to the Tigray region. Residence, sex of a child, mother's literacy status, household wealth index, and place of delivery were significant factors associated with receiving the third dose of PCV. Spatial analysis also showed the Somali and Afar regions had the lowest coverage, while the Addis Ababa and Tigray regions had higher coverage in both surveys.

Conclusion

Even though the coverage of the full PCV vaccine improved from 2016 to 2019, variation was observed among regions and between rural and urban areas. The wealth index and educational status of mothers were the most important determinants of PCV vaccine utilization. Hence, the mass campaign might boost coverage in nomadic and semi-nomadic regions and rural areas. Similarly, programs that narrow the gap due to low socioeconomic differences should be formulated and implemented to increase uptake and general coverage.

Using geographic information system to track children and optimize immunization coverage and equity in Karachi, Pakistan

BACKGROUND

Despite the potential of geospatial technologies to track and monitor coverage, they are underutilized for guiding immunization program strategy and implementation, especially in low-and-middle-income countries. We conducted geospatial analysis to explore the geographic and temporal trends of immunization coverage, and examined the pattern of immunization service access (outreach and facility based) by children.

METHODOLOGY

We extracted data to analyze coverage rates across different dimensions (by enrolment year, birth year and vaccination year) from 2018 till 2020 in Karachi, Pakistan using the Sindh Electronic Immunization Registry (SEIR). We conducted geospatial analysis to assess variation in coverage rates of BCG, Pentavalent (Penta)-1, Penta-3, and Measles-1 vaccines using Government targets. We also analyzed the proportion of children receiving their routine vaccinations at fixed centers and outreach and examined whether children received vaccinations at the same or multiple immunization centers.

RESULTS

A total of 1,298,555 children were born, enrolled or vaccinated from 2018 till 2020. At the district level, analysis by enrollment and birth year showed coverage increased between 2018 and 2019 and declined in 2020, while analysis by vaccination year showed consistent increase in coverage. However, micro-geographic analysis revealed pockets where coverage persistently declined. Notably 27/168, 39/168 and 3/156 Union councils showed consistently declining coverage when analyzing by enrollment, birth and vaccination year respectively. More than half (52.2%, 678,280/1,298,555) of the children received all their vaccinations exclusively through fixed centers and, 71.7% (499,391/696,701) received all vaccinations from the same centers.

CONCLUSION

Despite overall improving vaccination coverage between 2018 and 2020, certain geographic areas have consistently declining coverage rates, which is detrimental for equity. Making immunization inequities visible through geospatial analysis is the first step to ensure resources are allocated optimally. Our study provides impetus for immunization programs to develop and invest in geospatial technologies, harnessing its potential for improved coverage and equity.

Immunization Gender Inequity in Pakistan: An Analysis of 6.2 Million Children Born from 2019 to 2022 and Enrolled in the Sindh Electronic Immunization Registry

Gender-based inequities in immunization impede the universal coverage of childhood vaccines. Leveraging data from the Government of Sindh’s Electronic Immunization Registry (SEIR), we estimated inequalities in immunization for males and females from the 2019–2022 birth cohorts in Pakistan. We computed male-to-female (M:F) and gender inequality ratios (GIR) Tfor enrollment, vaccine coverage, and timeliness. We also explored the inequities by maternal literacy, geographic location, mode of vaccination delivery, and gender of vaccinators. Between 1 January 2019, and 31 December 2022, 6,235,305 children were enrolled in the SEIR, 52.2% males and 47.8% females. We observed a median M:F ratio of 1.03 at enrollment and at Penta-1, Penta-3, and Measles-1 vaccinations, indicating more males were enrolled in the immunization system than females. Once enrolled, a median GIR of 1.00 indicated similar coverage for females and males over time; however, females experienced a delay in their vaccination timeliness. Low maternal education; residing in remote-rural, rural, and slum regions; and receiving vaccines at fixed sites, as compared to outreach, were associated with fewer females being vaccinated, as compared to males. Our findings suggeste the need to tailor and implement gender-sensitive policies and strategies for improving equity in immunization, especially in vulnerable geographies with persistently high inequalities.

Patterns in the Prevalence of Unvaccinated Children Across 36 States and Union Territories in India, 1993-2021

IMPORTANCE

Children who do not receive any routine vaccinations (ie, who have 0-dose status) are at elevated risk of death, morbidity, and socioeconomic vulnerabilities that limit their development over the life course. India has the world's highest number of children with 0-dose status; analysis of national and subnational patterns is the first important step to addressing this problem.

OBJECTIVES

To examine the patterns among children with 0-dose immunization status across all 36 states and union territories (UTs) in India over 29 years, from 1993 to 2021, and to elucidate the relative share of multiple geographic regions in the total geographic variation in 0-dose immunization.

DESIGN, SETTING, AND PARTICIPANTS

This repeated cross-sectional study analyzed all 5 rounds of India's National Family Health Survey (1992-1993, 1998-1999, 2005-2006, 2015-2016, and 2019-2021) to compare the prevalence of children with 0-dose status across time-space and geographic regions. The Integrated Public Use of Microdata Series was used to construct comparable geographic boundaries for states and UTs across surveys. The study included a total of 125 619 live children aged 12 to 23 months who were born to participating women.

MAIN OUTCOMES AND MEASURES

The outcome was a binary indicator of children's 0-dose vaccination status, coded as children aged 12 to 23 months at the time of the survey who had not received the first dose of the diphtheria-tetanus-pertussis-containing vaccine. The significance of each geographic unit was computed using the variance partition coefficient (VPC).

RESULTS

Among 125 619 children, the national prevalence of those with 0-dose status in India decreased from 33.4% (95% CI, 32.5%-34.2%) in 1993 to 6.6% (95% CI, 6.4%-6.8%) in 2021. A substantial reduction in the IQR of 0-dose prevalence across states from 30.1% in 1993 to 3.1% in 2021 suggested a convergence in state disparities. The prevalence in the northeastern states of Meghalaya (17.0%), Nagaland (16.1%), Mizoram (14.3%), and Arunachal Pradesh (12.6%) remained relatively high in 2021. Prevalence increased between 2016 and 2021 in 10 states, including several traditionally high-performing states and UTs, such as Telangana (1.16 percentage points) and Sikkim (0.92 percentage points). In 2021, 53.0% of children with 0-dose status resided in the populous states of Uttar Pradesh, Bihar, and Maharashtra. A multilevel analysis comparing the share of variation at the state, district, and cluster (primary sampling unit) levels revealed that clusters accounted for the highest share of the total variation in 2016 (44.7%; VPC [SE], 1.04 [0.32]) and 2021 (64.3%; VPC [SE], 0.38 [0.12]).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, findings from approximately 3 decades of analysis suggest the need for sustained efforts to target populous states like Uttar Pradesh and Bihar and northeastern parts of India. The resurgence of 0-dose prevalence in 10 states highlights the importance of programs like Intensified Mission Indradhanush 4.0, a major national initiative to improve immunization coverage. Prioritizing small administrative units will be important to strengthening India's efforts to bring every child into the immunization regime.