Increasing Measles Vaccination Coverage Through Supplementation With an SQ-LNS Incentive in Children Aged 6-23 Months

Background/ Rational

Every year, hundreds of thousands of children are treated for severe wasting while experiencing repeated and prolonged outbreaks of vaccine-preventable illnesses, most notably measles. At least 20 million children annually still do not receive immunizations. Northeast Nigeria is at the epicentre of this dynamic, recording some of the worst malnutrition indicators and lowest vaccination coverage rates in the world.

Small-quantity lipid-based nutrient supplements (SQ-LNS) are a class of ready-to-use food supplements which are highly nutrient-dense and fortified designed for preventing malnutrition and improving child survival, growth, and development. A recent meta-analysis on SQ-LNS reveals that feeding a child just one sachet of SQ-LNS a day for a year can reduce their risk of mortality by 27%, and reduce cases of severe wasting by 31% and severe stunting by 17%. The overall strength of evidence on SQ-LNS benefits led the authors of a 2021 Lancet review to call scaling-up SQ-LNS a priority action.

Provision of SQ-LNS also holds promise in incentivizing vaccination as well as other health services.

Primary objective

To estimate the effectiveness of a SQ-LNS mass supplementation program added to routine immunization program compared to routine immunization program alone in terms of measles vaccine coverage, after 12 months of program implementation, in children aged 12-23 months in the end line cross-sectional household survey.

Main secondary objective

To estimate the effectiveness of a SQ-LNS mass supplementation program added to routine immunization program compared to routine immunization program alone in terms of measles vaccine coverage, after 12 months of program implementation, in children aged 6-12 months at inclusion in the longitudinal 12 months follow-up survey.

Secondary objectives

• To estimate the effectiveness of a SQ-LNS mass supplementation program added to routine immunization program compared to routine immunization program alone in children aged 6-23 months, after 12 months of program implementation, in terms of 1) all other infant vaccines' uptake, 2) timeliness of age-eligible vaccinations; 3) anthropometric status, 4) uptake of paediatric curative and preventive health consultations and activities.
• To assess the barriers and facilitators to SQ-LNS mass supplementation implemented as part of a routine immunization program in health facilities, from the perspectives of parents/legal guardian of children aged 6-23 months, health care providers and community health workers.
• To assess the cost-efficiency of a SQ-LNS mass supplementation program compared to routine immunization program in terms of cost per child supplemented and vaccinated.

Study sites : 20 wards covering the Karasuwa and Nguru Local Government Areas (LGAs) in Yobe state, Northeast Nigeria

Study design

A pragmatic parallel cluster randomized trial (PCT) with baseline measure with different populations and data collection modes: 1) baseline and end line cross-sectional household surveys of children aged 12-23 months, 2) a longitudinal follow-up survey (LS) of children aged 6-12 months at inclusion, 3) a qualitative feasibility and acceptability survey of parents of children aged 6-23 months, of health providers, of community health workers and community representatives and 4) a cost survey of parents/legal guardian of children from the longitudinal follow-up cohort, and 5) a health facility cost survey of a randomized subsample of health facilities.

Interventions compared

• The standard Expanded Program on Immunization (EPI) in children aged 6-23 months delivered according to the Ministry of Health's routine plans in the community and at health centres and health posts, named the standard EPI arm.
• The NutriVax program combining the EPI in children aged 6-23 months according to the Ministry of Health's routine plans in the community and at health centres (i.e. PHCCs) and health posts associated with SQ-LNS mass supplementation integrated into pre-existing services delivered at health centres (i.e. PHCCs) for children 6-23 months of age, named the NutriVax arm.

The unit of randomization (cluster) will be the ward and its catchment area. Clusters will be randomly allocated at a ratio of 1:1 either to the standard EPI arm or to the NutriVax arm.

Statistical analyses

Differences in measles vaccine coverage (dose 1) between control and intervention arms at end line will be assessed using multilevel regression models.

The study will be conducted in compliance with the protocol, the Declaration of Helsinki, the GCP guidelines and the Nigerian National Code for Health Research Ethics

Timeline : 2 years (December 2023-December 2025)

• Baseline and endline cross-sectional household surveys Inclusion criteria

• Aged 12-23 months;
• With oral informed consent of parent or legal guardian;
• Residing in the catchment settlements of wards included in the study. Exclusion criteria
• Included in the longitudinal follow-up.
• Longitudinal follow-up survey Inclusion criteria

• Aged 6-12 months;
• With written informed consent of parent or legal guardian;
• Residing in the catchment settlements of wards included in the study. Exclusion criteria
• Acute malnutrition criteria as per the WHO definition (i.e. MUAC< 125 or WHZ < -2 or nutritional edema);
• - Known medical complication that requires referral for hospitalization;
• Known allergies to SQ-LNS or SQ-LNS contraindication;
• Any other condition interfering with protocol adherence or the ability to give informed consent, in the judgment of the Field Investigator Sampling for HHS and LS will be carried out in three stages in each LGA using probability proportional to size (PPS).
• Qualitative feasibility and acceptability survey Inclusion

• Parent or legal guardian of a child aged 6-23 months and residing in the catchment settlements of wards included in the study, or Health worker of the ministry of health involved in the study,or Community representative or Community health workers;
• With written informed consent.