Early pandemic influenza (2009 H1N1) in Ho Chi Minh City, Vietnam: a clinical virological and epidemiological analysis. by Hien, T, Boni, M, Bryant, J, Ngan, T, Wolbers, M, Nguyen, T, Truong, N, Dung, N, Ha, D, Hien, V, Thanh, T, Nhu, L, Uyen, L, Nhien, P, Chinh, N, Chau, N, Farrar, J, Van Doorn, H, Ha, D, Nhu, L, Uyen, L