CD8A and infection: To investigate the contribution of effector T cells in mediating control of exoerythrocytic stages of P. chabaudi, antibodies to CD4+ or CD8+ T cells (anti-CD8β) or isotype control antibodies were administered to mice which had previously eliminated a P. chabaudi blood-stage infection, 3 days and 1 day prior to, and 1 day after sporozoite challenge (Fig. 3).