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.
Chan SY, Chew SH, Egawa K, Grussendorf-Conen EI, Honda Y, Rübben A, Tan KC, Bernard HU.Chan SY, et al.Virology. 1997 Dec 22;239(2):296-302. doi: 10.1006/viro.1997.8896.Virology. 1997.PMID: 9434721Free article.