Memory CD8 T cell responses exceeding a large but definable threshold provide long-term immunity to malaria. by Schmidt, N, Podyminogin, R, Butler, N, Badovinac, V, Tucker, B, Bahjat, K, Lauer, P, Reyes-Sandoval, A, Hutchings, C, Moore, A, Gilbert, S, Hill, A, Bartholomay, L, Harty, J