Survival of SCID mice infected with C. neoformans after the administration of mAbs. (A) SCID mice were more susceptible than the parental BALB/c strain (P < 0.001). (B) Average survival times and standard deviations for the IgG1-, IgG3-, and PBS-treated groups were 25.40 ± 2.50, 21.10 ± 2.47, and 26.80 ± 2.70 days, respectively. The 3E5 IgG1 mAb failed to protect SCID mice (P > 0.25), whereas the IgG3 mAb decreased survival (P < 0.001).