RT Journal Article SR Electronic T1 Low rates of immunity in adults behind H1N1 resurgence JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 410 OP 410 DO 10.1503/cmaj.109-4740 VO 186 IS 6 A1 Carolyn Brown YR 2014 UL http://www.cmaj.ca/content/186/6/410.abstract AB