Leaving no child behind? developing zero-dose and under-immunized child archetypes to improve vaccine uptake in...

Nigeria bears the highest burden of zero-dose and under-immunized children. This paper characterizes archetypes of zero-dose and under-immunized children in Nigeria through a stakeholder-engaged process, to inform policy and programmatic responses toward reaching the unreached.

A qualitative approach was used, comprising a rapid literature review and a qualitative survey over a two-day multi-sector stakeholder co-creation workshop. The workshop involved immunization stakeholders from a variety of sectors. Participants worked in near-homogenous groups to explore four archetypes of exclusion identified from literature, guided by a structured template. Narrative synthesis of group reports was performed and problem definitions for each archetype were discussed and validated in plenary.

Each archetype of zero-dose and under-immunized children were linked to broader determinants of health including poverty, education, geography and displacement. Children residing in hard-to-reach rural areas faced significant logistical barriers, difficult terrain and inadequate transportation options including long travel distances to reach health facilities. Urban poor children, while geographically closer to health centres, often encounter affordability issues, misinformation, and competing livelihood priorities of caregivers that hinder immunization uptake. For the conflict-affected, nomadic, and migrant children, frequent displacement, insecurity, and lack of stable healthcare access were reported as primary barriers. Culturally excluded children experience hesitancy due to religious or traditional beliefs, social stigma, and distrust of caregivers in modern medicine.

There are hidden dimensions of immunization inequity that should be fully explored in solving the problem of zero dose and non-vaccination. Addressing underlying causes of non-vaccination requires strengthened collaboration across sectors.