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.
Wilmshurst PT, Nuri M, Crowther A, Webb-Peploe MM.Wilmshurst PT, et al.Lancet. 1989 Jan 14;1(8629):62-5. doi: 10.1016/s0140-6736(89)91426-8.Lancet. 1989.PMID: 2562880