Association between maternal and infant class I and II HLA alleles and of their concordance with the risk of perinatal HIV type 1 transmission. by Polycarpou, A, Ntais, C, Korber, B, Elrich, H, Winchester, R, Krogstad, P, Wolinsky, S, Rostron, T, Rowland-Jones, S, Ammann, A, Ioannidis, J