An article from The New England Journal of Medicine, Volume 357:1685-1694, October 25, 2007 Number 17 by John C. Victor, Ph.D., M.P.H., Arnold S. Monto, M.D., Tatiyana Y. Surdina, M.D., Saida Z. Suleimenova, M.D., Gilberto Vaughan, Ph.D., Omana V. Nainan, Ph.D., Michael O. Favorov, M.D., Ph.D., Harold S. Margolis, M.D., and Beth P. Bell, M.D., M.P.H