What's New with Pandemic Flu

The term “bird flu” refers to avian influenza viruses. The recently emerged avian H7N9 influenza viruses replicate efficiently in birds and in mammals. Although H7N9 viruses rarely infect humans, they were the cause of sporadic human infections in China in 2014. In this review, we focus on the avian H7N9 influenza virus, summarize the characteristic biological features, and assess its pandemic potential. We also review information about highly pathogenic avian influenza viruses as possible sources of pandemic outbreaks.