Polysaccharide Antibody Deficiency: Specific or General?

To the Editor—Lopez et al [1] studied responses to pneumococcal capsular polysaccharides (PPSs) in 9 patients who had recovered from infection caused by an encapsulated bacterium. They showed that these individuals failed to mount appropriate antibody responses to ≥3 of 7 PPSs tested, and called this phenomenon "specific polysaccharide antibody deficiency."