A Literature Review and Proposed Learning Agenda on Immunisation-Nutrition Integration

"There is potential for nutrition and immunisation interventions to complement each other and increase coverage and equity of both nutrition and immunisation services."

This literature review report, published by the Eleanor Crook Foundation (ECF) and Gavi, the Vaccine Alliance, seeks to consolidate the latest evidence on the effectiveness of pairing nutrition interventions with vaccine delivery - also referred to as Immunisation-Nutrition Integration (INI) programmes - and the factors that influence their success. It also recommends a path forward for programming and further generation of evidence.

As explained in the review, "Infection and malnutrition form a vicious cycle, in which diseases deplete a body's nutrients and increase risk of malnutrition, while malnutrition reduces immune response and increases risk of serious infection and death. Immunisation and nutrition programmes are among the most cost-effective approaches to help children survive and thrive, but despite some successes in scaling these programmes, too many children still do not have access to the services they need – and in many cases, the children with the greatest risk of malnutrition are the same children who are under-immunised. Integrated Nutrition Immunisation (INI) programming is one approach to closing these gaps." However, as pointed out in the report, despite high-level political commitments and strong theoretical benefits of integration, there is limited consensus on "what works" in INI programming. This review attempts to fill this gap by consolidating the latest evidence on the effectiveness of INI programmes and the operational factors that influence their success.
 
For the purposes of the review, INI is defined as the "collaboration or coordination between immunisation and nutrition programmes with or without co-delivery of interventions at the same point of service." The review distinguishes between two main types of INI (which sometimes intersect) with slightly different rationales and operational requirements or enablers:
 

1. Combined service provision, where both immunisation and nutrition interventions are delivered in the same high-coverage health system touchpoint (i.e., "Supply-INI"). These approaches generate value primarily through efficiency, co-delivering compatible interventions that have overlapping priority populations.
2. Enhanced demand generation and case finding through a wider range of integrated approaches (i.e., "Demand-INI"), including joint demand generation, incentive approaches, and cross-referral. These approaches can increase programme reach by leveraging complementary strengths of immunisation and nutrition programmes.

This review of literature dating from 1980 to 2022 considered the following key questions:
 

• What is the evidence on the effectiveness and cost-effectiveness of the different types of INI for improved immunisation and nutrition outcomes?
• What are the operational considerations for effective INI?

Findings related to the evidence of effectiveness and cost-effectiveness of INI are discussed in relation to the effectiveness of integrating nutrition interventions
into immunisation services and the effectiveness of integrating immunisation into nutrition services, as well as the effectiveness of integrated health service delivery platforms where both immunisation and nutrition are delivered. 

Related to Supply-INI, the review, for example, found established evidence supporting the integration of vitamin A supplementation with immunisation programmes, including polio campaigns and supplementary immunisation activities. Yet other than this, there appears to be limited evidence of the effectiveness of nutrition interventions integrated with immunisation programmes. Two more recently published studies have looked at the feasibility of integration, but have not assessed impacts. One of them was Alive & Thrive, which piloted the delivery of nutrition-specific social and behaviour change (SBC) interventions by polio community mobilisation coordinators (CMCs) in Uttar Pradesh, India. The study concluded that integrating nutrition into the polio eradication platform was feasible and did not negatively impact polio immunisation rates. However, the study did not report on nutrition outcomes or cost savings from this approach.

Related to the Demand-INI (which involves generating demand and promoting health behaviours through broader, community-based platforms that are not solely designed for nutrition or immunisation), the review found that the care group approach, in which social and behaviour changes are promoted through peer-to-peer (mostly mother-to-mother) knowledge sharing was effective. The review found established evidence that using the care group approach to integrate health promotion and create demand for vaccination, nutrition services, and behaviour change positively impacts nutrition outcomes while simultaneously increasing coverage of diphtheria, pertussis, and tetanus dose one (DPT1), meningococcal vaccine (MCV), and tetanus toxoid vaccine (TT2).

Overall, the review states that "while the promise for INI is high and integration is taking place in many contexts, the formal evidence is surprisingly slim. First, most studies that have evaluated INI have examined either nutrition or immunisation outcomes but not both, even though a goal of integration is to ideally improve coverage rates of both programmes. Second, assessments of costs are necessary when deciding whether to pursue integration, yet there is a paucity of data in this area." 

In relation to operational conditions for effective INI, findings from the review reveal that nutrition interventions are best integrated with immunisation programmes if they include the following characteristics:
 

• Overlapping intervention age groups (i.e., where the age group for the vaccine matches or overlaps considerably with the age group for the nutrition intervention);
• Similar timing, duration, or frequency;
• Similar logistical requirements;
• High acceptability by beneficiaries and providers; and
• A similar skill level from health workers, or intervention is delivered through trained volunteers.

The review also revealed some of the factors that are necessary for successful integration, which are discussed in some detail in the report. They include: effective planning and coordination, enhanced health worker training, staffing for sustainable workloads, stakeholder buy-in and engagement, and monitoring and accountability. The review also highlights some of the enablers and barriers to successful integration through two case studies: one from a humanitarian setting in Sudan and the other from a maternal child health and nutrition (MCHN) programme in Uganda. 

Based on the findings, the review recommends that stakeholders deploy the most proven approaches but also proactively build the evidence base on opportunities for effective INI. In particular, the report suggests the following:
 

• Co-deliver highly compatible nutrition and immunisation interventions, building on the well-documented example of integrating vitamin A supplementation into immunisation platforms.
• Continue to support proven joint demand generation efforts at community level, such as the use of the care group approach.
• Explore high-potential INI opportunities when the logic for integration is strong - and simultaneously build the evidence base. In particular, the review recommends adopting a proactive learning agenda that includes the following priorities for reaching malnourished, under-immunised, or zero-dose children: test approaches where one programme's touchpoint is used to screen and refer children for the other programme; test approaches using nutrition services as an incentive for attending routine immunisation; and explore a broader learning agenda for reaching communities with high numbers of zero-dose children and high rates of malnutrition through an increased supply of integrated services combined with improved demand generation using evidence-based approaches. 
• Across all settings, generate evidence on the dual impact and cost-benefit of integration. This evidence would be crucial for guiding future policy and investment and for addressing the concerns of programme stakeholders related to the potential disruption to existing (often siloed) services that could be caused by INI.