RT Journal Article SR Electronic T1 Incidence of hospital admissions and severe outcomes during the first and second waves of pandemic (H1N1) 2009 JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association DO 10.1503/cmaj.100746 A1 Melissa Helferty A1 Julie Vachon A1 Jill Tarasuk A1 Rachel Rodin A1 John Spika A1 Louise Pelletier YR 2010 UL http://www.cmaj.ca/content/early/2010/11/08/cmaj.100746.1.abstract AB