Vaccination Strategies to Identify and Reach Zero-dose and Under-immunized Children in Crisis-affected States in Sudan: A Qualitative Study

"We consider [neighborhood committees] as key...I mean, for example, if there are cases of [vaccine] refusal, they notify us and then explain to [caregivers], urge them to vaccinate [their children] and inform them about the vaccination schedule." - governmental respondent at the state level

Globally, 21 million children were un- or under-vaccinated with Diphtheria-Tetanus-Pertussis (DTP)-containing vaccines in 2023. DTP3 immunisation coverage is a key indicator of a country's immunisation system performance and routine immunisation services for children. Around 20% of zero-dose children, those who had not received any DTP doses, live in conflict-affected settings in low- and middle-income countries (LMICs). This study aimed to map and assess current vaccination strategies to identify and reach zero-dose and under-vaccinated children in the crisis-affected states of South Kordofan, South Darfur, and Blue Nile in Sudan.

The researchers conducted a cross-sectional, qualitative study, using 20 in-depth interviews (IDIs) with governmental and non-governmental vaccination stakeholders at federal, state, and local levels. The interview topic guide was developed and structured using the IRMMA (Identify-Reach-Monitor-Measure-Advocate) framework developed by Gavi, the Vaccine Alliance. This framework is designed to help countries adopt a systematic approach to reaching zero-dose children and underserved communities, thereby promoting equitable access to primary health care. The data were collected in November and December 2022.

Respondents identified several underlying contextual factors contributing to the presence of zero-dose children in Sudan, including political instability, economic hardship, restrictions on donor funding, and the impact of the COVID-19 pandemic on routine vaccination services, thereby contributing to growing mistrust between recipients and providers. One said, "You tell them that immunization [childhood routine immunization] is important, and people should be immunized. Then, they come and ask about the vaccine, and you tell them it is unavailable. Tomorrow, they will come again and ask. This creates mistrust between the service provider and the person who receives the service."

Results indicate that zero-dose and under-immunised children in the study sites were concentrated in opposition-controlled areas, nomadic communities, and remote rural areas. Participants attributed the high prevalence of zero-dose children in these communities to limited contact with vaccination services, stemming from either poor physical accessibility or low demand for such services. Sociocultural barriers to reaching zero-dose children were reported, with one participant saying that some mothers report they do not allow men to enter their houses to vaccinate their children. Reported context-specific challenges included geographic barriers to reaching remote rural communities and "insecurity" due to local armed clashes.

Other challenges highlighted by participants are social norm and cultural issues related to the nomadic population in the study, such as those articulated in this quotation from a governmental respondent: "[Nomadic communities] believe that when one of them says he has 5 or 6 children, they may attract the evil eye [from strangers]...meaning that children are at risk of dying because there are so many. That's why they hide [the true number of children in the family]." This "evil eye" issue is very common in the Sahel region and hinders efforts to reach these groups - not only with regard to vaccination but also other health services. 

Participants reported that identifying zero-dose and under-immunised children in accessible areas is carried out as part of the micro-planning process at state and locality levels. Various strategies were used in inaccessible areas, including;

• Collaboration with trusted non-governmental organisations (NGOs) and key individuals, such as community and tribal leaders, who are respected by both local governments and opposition groups. These leaders work together with community-based organisations and volunteers to identify zero-dose children through coverage surveys and home visits.
• The training of local volunteers, particularly young mothers, to conduct various identification activities. These activities included mobilising the community, translating vaccination information from Arabic to local languages, identifying zero-dose and under-immunised children at social events, and assisting with vaccination coverage surveys.

Participants identified several strategies for delivering vaccination services to zero-dose children. In accessible areas, three main approaches are used: fixed centres, outreach, and mobile teams. For remote and inaccessible areas, local strategies include collaboration with trusted NGOs, community and tribal leaders, as well as the ad-hoc integration of vaccination campaigns with other health interventions, such as nutrition programmes, COVID-19 vaccination campaigns, house-to-house polio vaccination campaigns, and insecticidal net distribution. The latter strategy (integration) requires proper coordination, either internally with nutrition or malaria programmes, or externally to track nomadic populations.

The study participants appeared to lack defined strategies for the measurement and monitoring of zero-dose and under-immunised children. Respondents also conflated advocacy with mobilisation, and advocacy was broadly characterised as an ad hoc activity mostly connected to immunisation campaigns.

In conclusion, this study underscores the complexity of vaccinating zero-dose and under-immunised children in crisis-affected states of Sudan. Further research is needed to evaluate these practices and the role of NGOs and community engagement in improving vaccination coverage. Furthermore, exploring alternative funding methods and using geographic information systems (GIS) could enhance vaccination data and address funding limitations.