In a frantic race to find substances to combat the most recent H1N1 outbreak, scientists have been looking to botanicals. In this study they found that Echinacea pupurea not only inhibited H1N1 by preventing its ability to enter cells (in vitro), but inactivated the virus as well. In addition, Echinacea inhibited the highly pathogenic avian influenza virus (H5N1, H7N7). The clincher is that it even worked against Tamiflu resistant strains! Also, Echinacea didn’t seem to develop resistant strains of H1N1. One caveat is that it worked best if it was taken prior to contact with the virus. Therefore it should be taken as a preventative and may not work as well after the fact.
 
Virol J. 2009 Nov 13;6(1):197. [Epub ahead of print]