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.
Marcus PI, Sekellick MJ.Marcus PI, et al. Among authors: sekellick mj.J Gen Virol. 1978 Mar;38(3):391-408. doi: 10.1099/0022-1317-38-3-391.J Gen Virol. 1978.PMID: 204729