Limited antigenic diversity of Plasmodium falciparumapical membrane antigen 1 supports the development of effective multi-allele vaccines by Terheggen, U, Drew, DR, Hodder, A, Cross, N, Mugyenyi, C, Barry, A, Anders, R, Dutta, S, Osier, F, Elliott, SR, Senn, N, Stanisic, D, Marsh, K, Siba, P, Mueller, I, Richards, J, Beeson, J