The immune system (led by the white blood cells, that communicate with other white blood cells that there is a fight ongoing) generates proteins that are called antibodies. They attach themselves to the virus and try to disable that pathogen. There are not enough white blood cells to rid the body of the influenza virus but there are enough antibodies to do the trick -- it just takes time, up to two weeks in most cases (www.ifpma.org) (www.solvay-influenza.com).
References
Centers for Disease Control and Prevention. "Transmission of Influenza Viruses from Animals
To People / Types of Influenza Viruses / Flu symptoms & Severity / How the Flu Virus
Can Change: 'Drift' and 'Shift'." Retrieved Dec. 8, 2010, from http://www.cdc.gov.
International Federation of Pharmaceutical Manufacturers & Associations....
9, 2010, from http://www.ifpma.org/index.php?id=4176. (2010).
Kimball, John. "The 'Flu' / The Influenza A Virus." Retrieved Dec. 8, 2010, from http://users.rcn.com/jkimball.ma.ultranet/biologypages/l/influenza.html. (2009).
Solvay -- Influenza.com. "Complications of Influenza." Retrieved Dec. 9, 2010, from http://www.solvay-influenza.com/aboutinfluenza/riskofinfluenza/0,,2653-2-0,00.htm.
(2010)
University of Cape Town. "Influenza." Retrieved Dec. 8, 2010, from http://web.uct.ac.za/depts/mmi/jmoodle/influen2.html.
University of Queensland. "Virology Down Under: Human Viruses: what they are, how they tick and the illnesses associated with them / Influenza Virus." Retrieved Dec. 9, 2010, from http://www.uq.ed.au/vdu/VDUinfluenza.htm.
