REACH-OUT

The challenge

Vaccination is a proven lifesaver, and national immunisation programmes in sub-Saharan Africa now deliver dozens of vaccines to protect infants against a variety of deadly infectious diseases, including measles, pertussis and diphtheria. However, reaching every infant is highly challenging. In particular, some communities can be very hard to reach or may be reluctant to take up vaccination services. 

So-called zero-dose children, who do not receive any infant vaccinations, are at risk of multiple vaccine-preventable diseases. In addition, they often live in communities that have limited access to any kind of health services. Globally, zero-dose children account for a third of all childhood deaths.

There are multiple possible reasons why a community has a high proportion of zero-dose children, including both supply-side barriers affecting access to vaccines and demand-side barriers affecting take-up. Understanding these reasons is essential if effective ways to reduce the number of children with zero doses are to be introduced by immunisation programmes.

The project

The REACH-OUT project is working with national immunisation programmes and other stakeholders in Kenya, Nigeria and Rwanda to better understand the root causes of under-vaccination and to design locally tailored interventions to address key issues and increase vaccination rates.

One key challenge is to identify where zero-dose children are most likely to be found and what the determinants of poor vaccination are. The project is addressing these questions in different ways. A range of data will be collated to develop integrated geospatial and epidemiological models that create high-resolution maps of ZD prevalence and infection risks. Other geospatial information will also be collated, including the location of immunisation facilities and the distribution of other variables affecting immunisation service delivery and take-up.  

It is also gathering and analysing new data to understand the factors influencing the supply of and demand for immunisation services. These data include a survey of caregivers on the behavioural and social determinants of vaccination, as well as interviews and focus groups with health providers at different levels of the immunisation programme. This new evidence will be used as a basis to inform the participatory design of more effective service delivery interventions. A novel digital tool will also be developed to help health facility workers identify and reach zero-dose children within their catchment area. 

Extensive consultations will be undertaken with immunisation experts, local immunisation programme staff, and community representatives to identify potential interventions that could be included in a package. These co-created packages will then be piloted, implemented and evaluated in the three countries. 

Impact will be assessed using a stepped wedge trial design, in which the package of interventions will be sequentially introduced across different areas, with sites scheduled for later implementation serving as controls for early implementing sites. Multiple measures of impact will be tracked, including total coverage, reductions in zero-dose numbers, and impacts on the equity of vaccination coverage. The trial design also creates an opportunity to study factors associated with the successful implementation of the new interventions.  Alongside the trial, a distributional cost-effectiveness analysis will be conducted to assess the value for money of the defined interventions and their equity impacts. 

Impact

The REACH-OUT project will generate evidence on the causes of under-immunisation and the effectiveness of strategies to address them. It will: 

• Provide new tools to enable programmes to gain a clearer picture of where zero-dose children are likely to live.
• Generate evidence on the effectiveness of a range of interventions to improve access to and take-up of immunisation services.
• Highlight key factors affecting the success of implementation at the scale of such interventions.
• Identify contextual factors that influence impact, to guide adaptation of interventions to other settings.

By enabling immunisation programmes to identify and reach zero-dose children, the REACH-OUT project will ensure that more vulnerable infants receive life-saving vaccines and fewer die unnecessarily from vaccine-preventable diseases.