Interested in the nitty-gritty details of avian influenza H5N1? This article discusses the major genetic features and evolution without being overly technical. One interesting feature is the description of how vaccine strains are being created using "reverse genetics".
The World Health Organization Global Influenza Program Surveillance Network. Evolution of H5N1 avian influenza viruses in Asia. Emerg Infect Dis [serial on the Internet]. 2005 Oct. Available from http://www.cdc.gov/ncidod/EID/vol11no10/05-0644.htm