Subcytotoxiclevels of SLO have been found to suppress neutrophil oxidative bursts,enabling GAS to resist cell killing.20 Immunizationwith SLO toxoid can counteract this inhibitory effect, although theprotection in certain challenge models falls short compared to M proteinimmunization.21 Moreover, SLO-deficientGAS strains exhibit decreased virulence in mouse infection models,22 while antisera from SLO toxoid-immunized micecan protect naïve mice against challenges with wild-type GASstrains.18 The gene discussed is KCNMA1; the disease is infection.