Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico Por Miranda-Novales, G, Arriaga-Pizano, L, Herrera-Castillo, C, Pastelin-Palacios, R, Valero-Pacheco, N, Pérez-Toledo, M, Ferat-Osorio, E, Solórzano-Santos, F, Vázquez-Rosales, G, Espitia-Pinzón, C, Zamudio-Lugo, I, Meza-Chávez, A, Klenerman, P, Isibasi, A, López-Macías, C