Searching for sharp drops in the incidence of pandemic A/H1N1 influenza by single year of age. oleh Jessica Hartman Jacobs, Brett Nicholas Archer, Michael G Baker, Benjamin J Cowling, Richard T Heffernan, Geoff Mercer, Osvaldo Uez, Wanna Hanshaoworakul, Cécile Viboud, Joel Schwartz, Eric Tchetgen Tchetgen, Marc Lipsitch