2009 Influenza A(H1N1) seroconversion rates and risk factors among distinct adult cohorts in Singapore

Mark I.C. Chen, Vernon J.M. Lee, Wei Yen Lim, Ian G. Barr, Raymond T.P. Lin, Gerald C.H. Koh, Jonathan Yap, Cui Lin, Alex R. Cook, Karen Laurie, Linda W.L. Tan, Boon Huan Tan, Jimmy Loh, Robert Shaw, Chris Durrant, Vincent T.K. Chow, Anne Kelso, Kee Seng Chia, Yee Sin Leo