AIM: To test the efficacy of T-cell-dependent and T-cell-independent vaccines in rural Gambian children suffering from a range of energy/protein and micronutrient deficiencies. METHODS: Nutritional status (anthropometry, haemoglobin, plasma leptin and micronutrient status) and response to two vaccinations (23 valent pneumococcal capsular polysaccharide vaccine, Pneumovax and the Human Diploid-Cell Rabies Vaccine) were assessed in 472 children aged 6 1/2 h to 9 1/2 y. RESULTS: Anthropometry and micronutrient status (as z-scores against European reference values) indicated a range from moderate to severe levels of undernutrition [mean (interquartile range): weight-for-age z-score -1.58 (-2.18 to -0.95); height-for-age z-score -0.94 (-1.51 to -0.35); body-mass-index-for-age z-score -1.43 (-2.05 to -0.84); mid-upper arm circumference -1.41 (-1.72 to -1.13); leptin -1.06 (-1.10 to -1.03); haemoglobin (Hb) -0.30 (-1.18 to 0.79); zinc -1.29 (-2.42 to -0.55); vitamin C -0.01 (-1.18 to 1.15); retinol -1.33 (-1.97 to -0.77)]. A seasonal effect was observed in haemoglobin levels and in all micronutrients (with the exception of zinc and retinol) and in the response to vaccination. After adjusting for seasonality, age and gender, no consistent associations were found between any of the measures of nutritional status and the effectiveness of seroconversion to either of the vaccines. CONCLUSION: The successful short-term seroconversion to whole inactivated viral and bacterial polysaccharide vaccines indicates that the processes leading to antibody secretion remain intact over a wide range of single and combined nutrient deficiencies.