New swine flu virus with 'pandemic potential' found in China: Study

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Amid the novel coronavirus pandemic that has spread to at least 188 countries infecting over one crore people, researchers in China have discovered a new type of swine flu virus that is capable of triggering a pandemic.

According to a study published in the US science journal Proceedings of the National Academy of Sciences (PNAS), researchers are concerned that the new flu could mutate further so that it can spread easily from person to person, and trigger a global outbreak.

Named G4, it is genetically descended from the H1N1 strain that caused the swine flu pandemic in 2009.

“We report on an influenza virus surveillance of pigs from 2011 to 2018 in China, and identify a recently emerged genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus, which bears 2009 pandemic (pdm/09) and triple-reassortant (TR)-derived internal genes and has been predominant in swine populations since 2016,” said the researchers.

Results of blood tests showed that more than 10 percent of swine workers were positive for the G4 EA H1N1 virus.

According to the study, serological surveillance among occupational exposure population showed that 10.4 percent (35/338) of swine workers were positive for G4 EA H1N1 virus, especially for participants in the age between 18 years to 35 years, who had 20.5 percent (9/44) seropositive rates, indicating that the predominant G4 EA H1N1 virus has acquired increased human infectivity.

“Such infectivity greatly enhances the opportunity for virus adaptation in humans and raises concerns for the possible generation of pandemic viruses,” scientists said.

The virus possesses “all the essential hallmarks of a candidate pandemic virus,” they said. Any immunity human beings gain from exposure to seasonal flu does not provide protection from G4, added the researchers.

“Similar to pdm/09 virus, G4 viruses bind to human-type receptors, produce much higher progeny virus in human airway epithelial cells, and show efficient infectivity and aerosol transmission in ferrets. Moreover, low antigenic cross-reactivity of human influenza vaccine strains with G4 reassortant EA H1N1 virus indicates that preexisting population immunity does not provide protection against G4 viruses,” scientists stated in the study.