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.
Schulze K, Goldmann O, Toppel A, Medina E, Guzmán CA.Schulze K, et al. Among authors: toppel a.Vaccine. 2005 Feb 3;23(11):1408-13. doi: 10.1016/j.vaccine.2004.08.045.Vaccine. 2005.PMID: 15661390
Medina E, Goldmann O, Toppel AW, Chhatwal GS.Medina E, et al. Among authors: toppel aw.J Infect Dis. 2003 Feb 15;187(4):597-603. doi: 10.1086/373998. Epub 2003 Feb 7.J Infect Dis. 2003.PMID: 12599076
Toppel AW, Rasmussen M, Rohde M, Medina E, Chhatwal GS.Toppel AW, et al.J Infect Dis. 2003 Jun 1;187(11):1694-703. doi: 10.1086/375029. Epub 2003 May 15.J Infect Dis. 2003.PMID: 12751026