Fig. 1From: A longitudinal study of natural antibody development to pneumococcal surface protein A families 1 and 2 in Papua New Guinean Highland children: a cohort studyGeometric mean concentrations (GMC) of IgG responses to PspA1 (a) and PspA2 (b) in relation to age. Error bars indicate 95Â % confidence intervals of the GMC. PspA, pneumococcal surface protein A; AU/ml, arbitrary ELISA units/ml Back to article page