Increasing measles vaccination coverage through supplementation with an SQ-LNS incentive in children aged 6 to 23 months: study protocol of NutriVax-Measles, a superiority pragmatic parallel cluster-randomized controlled trial in Yobe State, Northern Nigeria

This protocol describes a two-arm cluster-randomized trial in Yobe State, Nigeria, evaluating whether integrating small-quantity lipid-based nutrient supplements (SQ-LNS) into routine immunization services increases measles vaccination coverage among children aged 6-23 months. The trial aims to provide evidence on a dual-purpose intervention addressing undernutrition and low immunization coverage.

C. Cazes; B. W. Goni; N. Muhammad; D. Gabillard; Pierrot Kalubi Balonda; Loic Feuzeu; Irine Atanga; Brice Yapi; G. Habiyambere; Serge Danho; Eric Balestre; Katherine P. Adams; M. Plazy; K. Phelan; R. Becquet· Trials· 2025· DOI 10.1186/s13063-025-09243-5

The core problem

Undernutrition and infectious diseases form a vicious cycle that poses a dual threat to vulnerable children in low- and middle-income countries. Measles remains a major cause of child mortality, and vaccination coverage in many regions is suboptimal. In Yobe State, Northern Nigeria, high rates of undernutrition and low immunization coverage persist as major public health challenges. Innovative strategies are needed to simultaneously address these intertwined issues. This trial, NutriVax-Measles, aims to evaluate whether distributing small-quantity lipid-based nutrient supplements (SQ-LNS) as an incentive alongside routine immunization can increase measles vaccination coverage. The hypothesis is that SQ-LNS, known for its nutritional benefits, may also serve as a motivator for caregivers to bring their children for vaccination, thereby improving uptake.

Innovation

The study is designed as a two-arm superiority pragmatic parallel cluster-randomized controlled trial with baseline measures. It will be conducted in 20 wards of Nguru and Karasuwa Local Government Areas, Yobe State, Northeast Nigeria. Wards will be randomly allocated 1:1 to either the standard National Program on Immunization (NPI) arm or the NutriVax arm, which combines NPI with SQ-LNS distribution. The intervention will be implemented for up to 12 months. Measles immunization coverage will be assessed at two levels: population-level coverage in children aged 12-23 months (primary outcome) via an endline cross-sectional survey, and individual-level coverage in children aged 6-12 months (key secondary outcome) via a longitudinal survey. Each cross-sectional survey (baseline and endline) will include 1560 participants, while the longitudinal survey will enroll 600 participants. Sampling will use a multi-stage design with probability proportional to size and systematic random household selection. All outcomes will be analyzed by intention-to-treat. Qualitative interviews will assess feasibility and acceptability. Cost-efficiency differences between arms will be estimated using an incremental cost-efficiency ratio. The trial is registered with ClinicalTrials.gov (NCT06387511).

Introduction

Undernutrition and infectious diseases form a vicious cycle that poses a dual threat to vulnerable children in low- and middle-income countries. Measles remains a major cause of child mortality, and vaccination coverage in many regions is suboptimal. In Yobe State, Northern Nigeria, high rates of undernutrition and low immunization coverage persist as major public health challenges. Innovative strategies are needed to simultaneously address these intertwined issues. This trial, NutriVax-Measles, aims to evaluate whether distributing small-quantity lipid-based nutrient supplements (SQ-LNS) as an incentive alongside routine immunization can increase measles vaccination coverage. The hypothesis is that SQ-LNS, known for its nutritional benefits, may also serve as a motivator for caregivers to bring their children for vaccination, thereby improving uptake.

Why it matters

This trial is the first to evaluate whether a preventive nutrition supplement can also serve as an incentive to increase vaccination coverage. By integrating SQ-LNS distribution into routine immunization services, the intervention addresses both undernutrition and low vaccine uptake. If effective, this dual-purpose approach could be a cost-efficient strategy for governments and donors in settings where these challenges persist. The findings will inform policy and programmatic decisions, potentially leading to scalable solutions that leverage existing immunization platforms. The pragmatic design ensures real-world applicability, and the mixed-methods approach provides a comprehensive evaluation of impact, feasibility, and cost. Limitations include the cluster-randomized design, which may introduce confounding, and the reliance on self-reported vaccination status, though efforts will be made to verify through health cards. Overall, the trial has the potential to significantly impact public health practice in similar contexts.

Who should read this

Praktisi kesehatan, peneliti klinis, dan pembaca Research Digest.

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