CD8A and infection: These phenotypic alterations are functionally relevant, as memory T cells in these B cell–deficient/restricted hosts are defective in their persistence to memory time points and in their capacity for host protection (1), consistent with previously published data on CD8+ T cell memory after infection of B cell–deficient mice with LCMV (3, 4), intranasal vaccinia virus (VV) (16), or LM (5).