This observation is consistent with previous reports supporting the concept that PSs are usually poorly degradable, mostly stimulate mature B cells and often do not elicit responses in neonates.37 But increases of serum IgA and IgE in SCD children postvaccination might suggest that not only IgM memory B cells are solely responsible for anti-PS antibody production. This evidence concerns the gene CD40LG and Schnyder corneal dystrophy.