H7N9 is a bird flu strain of the species Influenza virus A ( avian influenza virus or bird flu virus ) .

An H7N9 virus was first reported Reporting to have infected humans in March 2013 , in China .

A 5th epidemic of the H7N9 virus began Process_start in October 2016 in China .

The CDC estimates that the H7N9 virus has the greatest potential compared with other influenza A viruses to cause Causation a pandemic , although the risk is low , because like other type A viruses , it is not easily transmitted between people in its current form .

The World Health Organization ( WHO ) has identified Check H7N9 as `` ... an unusually dangerous virus for humans . ''

It has been established Building that many of the human cases of H7N9 appear to have a link Connect to live bird markets .

H7N9 virus does not kill Killing poultry , which makes Causation surveillance much more difficult .

Chinese scientists announced Expressing_publicly the development of a vaccine on October 26 , 2013 , but said Telling that H7N9 had not spread Dispersal far enough to merit widespread vaccination .