Summary
A cluster-randomized trial in northern Nigeria found higher card-verified measles vaccination coverage when small-quantity nutrient supplements were offered alongside routine immunization. The study tested a delivery strategy in 20 clusters, not the effect of the supplement alone.
A pragmatic cluster-randomized trial in Yobe State, northern Nigeria, found higher measles-vaccine uptake among children in areas where small-quantity lipid-based nutrient supplements were offered alongside routine immunization. At the end of the study, 55.3% of children aged 12–23 months in the intervention arm had a vaccination-card record of their first measles-containing vaccine dose (MCV1), compared with 41.2% in control areas. The trial tested the combined NutriVax delivery strategy; it did not isolate the effect of taking the supplement itself.
How NutriVax was delivered
Researchers randomly assigned 20 health-area clusters across two Local Government Areas to routine National Program of Immunization services alone or to those services plus NutriVax. In intervention areas, eligible children received a monthly ration of small-quantity lipid-based nutrient supplements (SQ-LNS) at primary healthcare centres. The ration was intended to provide one sachet per day; caregivers in hard-to-reach areas could receive a supply for three months. Supplementation was voluntary and was not conditional on accepting a vaccine.
The researchers assessed vaccination coverage through household surveys before the intervention and at endline. The endline survey, conducted in May 2025, included 1,604 children: 801 in control clusters and 803 in NutriVax clusters. Although the programme reached children in its eligible age range, 48% of children surveyed in the intervention arm had ever received SQ-LNS by endline. The primary outcome was MCV1 coverage verified by vaccination card among children aged 12–23 months. In the primary analysis, a child without a card, or with no MCV1 entry on the card, was counted as unvaccinated.
Vaccination coverage rose, but remained below the target
Card-verified MCV1 coverage rose from 25.0% to 55.3% in the NutriVax arm and from 29.9% to 41.2% in the control arm between the baseline and endline surveys. The primary mixed-effects analysis estimated that the odds of card-verified MCV1 receipt were higher in NutriVax clusters (odds ratio 2.08, 95% confidence interval 1.30–3.35; P = 0.004). A separate difference-in-differences analysis estimated a 20.1 percentage-point increase from baseline relative to control clusters (95% CI 13.7–26.5; P < 0.0001). This is a modelled change relative to the control group, not the raw difference between the two arms at endline.
The study also reported improvements in several other measures, including card retention and coverage of some additional vaccines. These findings are consistent with the strategy bringing more families into contact with routine services, but the study compared the whole NutriVax approach with routine services—not supplement recipients with non-recipients. Because supplement uptake was voluntary, that recipient-level comparison would not have the protection of random assignment.
The result is promising for settings facing both undernutrition and low immunization coverage, but the intervention did not bring coverage close to the 95% level discussed by the researchers as needed for measles population protection. The trial took place in one country and operated with support to maintain supplies of supplements and vaccines, so the size of the effect may depend on local service access and reliable supply. It also measured documented vaccine receipt, rather than immune response or protection from measles. The findings support further consideration of integrated nutrition and immunization delivery in similar settings, while leaving open how well the approach would transfer to other health systems.