February 2025 — Every year, millions of children under the age of five die from preventable diseases, with immunization being one of the most effective interventions to combat this crisis. Despite significant global progress, Tanzania remains one of the countries struggling with high numbers of zero-dose and undervaccinated children. In 2022, Tanzania was ranked among the top ten African nations with the highest number of zero-dose children, highlighting a critical gap in public health efforts. This article delves into a groundbreaking study that employs Human-Centered Design (HCD) to tackle this pressing issue in the Ilala District of Dar es Salaam. 

Objectives

The primary aim of the study was to use the HCD approach to identify, prioritize, and implement community-centric interventions to increase vaccine demand and reduce the zero-dose gap by at least 50% in the Ilala District.

Methods

The study involved co-creation workshops with 483 participants, including caregivers, community health workers (CHWs), healthcare providers, and local leaders. The UNICEF Journey to Health and Immunization framework was followed to identify barriers and enablers influencing vaccination uptake.

Key Findings

Barriers to Vaccination

• Community Leaders: Inadequate support from local leaders in vaccination sensitization and surveillance.

• Infrastructure: Poor infrastructure, especially in new settlement areas, hinders access to vaccination services.

• Parental Hesitancy: Hesitancy and unwillingness of parents/guardians to vaccinate their children.

• Resource Constraints: Limited availability of resources for mobile immunization services.

Solutions Identified

Through brainstorming sessions, 309 ideas were generated and refined into three main solutions:

1. Notification System: Health facilities to notify local leaders about vaccination dates.

2. Influence Campaign: Using vaccinated individuals to influence others to get vaccinated.

3. Advocacy by Leaders: Engaging local government leaders and house representatives for vaccine advocacy.

Implementation

The advocacy strategy involving local government leaders and house representatives was implemented. This included home-to-home interpersonal sensitization and vaccination services. The initiative reached 67,145 houses (104% of the target) and sensitized 131,088 families (83% of the target).

Impact and Effectiveness

The HCD framework proved effective in increasing collaboration with local leaders and community ownership of the vaccination initiative. The initiative successfully increased vaccination coverage, demonstrating the effectiveness of the HCD approach.

Recommendations for Future Research

Future research should conduct similar studies in diverse settings to identify more nuanced community-specific challenges. The Ministry of Health and relevant stakeholders should institutionalize HCD as a core component of the immunization strategy.

Conclusion

Reducing the zero-dose gap and the number of under-vaccinated children in Tanzania requires innovative, ethical, and practical approaches like HCD. The house-to-house campaigns implemented as part of the proposed community-centric interventions raised awareness, increased vaccine uptake, and strengthened the community’s role in health advocacy. This demonstrates that applying HCD principles in public health interventions can effectively tackle challenges like zero-dose vaccination while fostering community engagement and sustainable change.

By adopting the HCD approach, Tanzania can make significant strides in improving immunization coverage and reducing under-five mortality rates, ultimately contributing to better health outcomes for its children.

Read the full study here.