Prevalence of pneumococcal SSA associates with the need for continuous IgGRT and infections. (A) Prevalence of SSA in study participants and the association with IgG2 plasma levels. (B) Number of detected SSA and plasma levels of IgG2, in patients with the need for and without the need for continuous IgGRT after the discontinuation trial, respectively. (C) Percentages of SSA at protective levels (>0.35 mg/L) in groups of patients with low incidence or high incidence of infections (i.e., more than one airway infection treated with antibiotics or any infection requiring hospitalization) when off IgGRT. Mann–Whitney test or Fisher’s test was used for statistical analyses.