Fig. 3

Anti-PRP IgG titres for the 6 cases of vaccine failure among children under the age of 5 years. Titres are given in μg/ml at the admission and 1 month post infection. The data represent each individual tested serum as scattered points around the mean (solid lines). The dotted lines indicate the threshold of 0.15 μg/ml and 1 μg/ml. P value was calculated using Mann-Whitney test