Coronavirus: New G4 swine flu strain could trigger next pandemic: study

A new flu strain found in pigs in China has ‘all the essential hallmarks of being highly adapted to infect humans’.

Pigs resting in a pen at a pig farm in Yiyang county, in China's central Henan province in 2018. 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. Picture: Greg Baker/AFP

A new strain of swine flu with the potential to trigger a pandemic in humans has been discovered, according to research.

Named G4, it is descended from the H1N1 strain that caused a pandemic in 2009, a study in the American science journal PNAS shows. The strain has “all the essential hallmarks of being highly adapted to infect humans”, according to the authors, who are from Chinese universities and the Centre for Disease Control and Prevention in China.

The researchers found that 10 per cent of 338 swine workers had tested positive for the virus, especially in the 18 to 35 age group, an indication that the virus “has acquired increased human infectivity”. The study found that 4.4 per cent of the general population appeared to have been exposed.

There was no evidence yet that the strain could pass from human to human but the team wrote that “such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses”.

From 2011 to 2018 researchers took 30,000 nasal swabs from pigs, allowing them to isolate 179 swine flu viruses.

G4 was observed to be highly infectious, replicating in human cells and causing more serious symptoms in ferrets, which are widely used in tests, than other viruses. Tests also showed that any immunity humans gain from exposure to seasonal flu did not provide protection against G4.

A Chinese foreign ministry spokesman said the government had “been paying close attention to its development” and would take action to prevent its spread and any outbreaks.

In the fight against the coronavirus, authorities in Beijing have extended the quarantine period for high-risk groups to 28 days, amid fears that the strain that triggered the city’s latest outbreak is far more contagious.

The Times