New swine flu in China has pandemic potential

Washington: Researchers in China have discovered a new type of swine flu that is capable of triggering a pandemic, according to a study published in the US science journal PNAS.

Named 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.

From 2011 to 2018, researchers took 30,000 nasal swabs from pigs in slaughterhouses in 10 Chinese provinces and in a veterinary hospital, allowing them to isolate 179 swine flu viruses.

The majority were of a new kind which has been dominant among pigs since 2016.

The researchers then carried out various experiments including on ferrets, which are widely used in flu studies because they experience similar symptoms to humans -- principally fever, coughing and sneezing.

G4 was observed to be highly infectious, replicating in human cells and causing more serious symptoms in ferrets than other viruses.

Tests also showed that any immunity humans gain from exposure to seasonal flu does not provide protection from G4.