marginally significantP = .055
Having had prior influenza was marginally significant as a risk for season 1 influenza in cases versus controls ( P = .055), yet a significant risk factor in controls for season 2 ( P = .018).
Having had prior influenza was marginally significant as a risk for season 1 influenza in cases versus controls ( P = .055), yet a significant risk factor in controls for season 2 ( P = .018).
21 Having had influenza B may not have been as protective against the new strain as having had influenza A in season 1, although the difference did not reach statistical significance.