Researchers in China have discovered a new type of swine flu that is capable of triggering a pandemic. This information is according to a study published on June 28 in the US science journal PNAS. Titled G4, it is genetically descended from the H1N1 strain that caused a pandemic in 2009. It possesses "all the essential hallmarks of being highly adapted to infect humans," say the authors, scientists at Chinese universities and China's Center for Disease Control and Prevention. G4 was observed to be highly infectious, replicating in human cells and causing more serious symptoms in ferrets than other viruses. Watch the video to know more.