An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Cauchemez S, Bhattarai A, Marchbanks TL, Fagan RP, Ostroff S, Ferguson NM, Swerdlow D; Pennsylvania H1N1 working group.Cauchemez S, et al. Among authors: swerdlow d.Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):2825-30. doi: 10.1073/pnas.1008895108. Epub 2011 Jan 31.Proc Natl Acad Sci U S A. 2011.PMID: 21282645Free PMC article.