A new strain of swine flu found in China that has been feared might spark another pandemic has been branded as “very dangerous” by researchers.
Called genotype 4, or G4 for short, the virus strain is genetically descended from the swine flu pandemic that gripped the world in 2009.
According to scientists at China’s Centre for Disease Control and Prevention and universities in the communist nation, the strain possesses “all the essential hallmarks of being highly adapted to infect humans”.
Researchers have spent seven years taking thousands of swabs from pigs in slaughterhouses across China, which allowed them to find and isolate 179 swine flu viruses.
It is understood the new strain has existed among pigs since 2016.
Scientists found the virus to be highly infectious and that immunity from seasonal flu does not protect from G4.
Professor James Wood, an infectious diseases expert at Cambridge University, said the discovery showed how easily viruses – like coronavirus and swine flu – can jump from one species to another.
He said: “The work comes as a salutary reminder that we are constantly at risk of new emergence of zoonotic pathogens and that farmed animals, with which humans have greater contact than with wildlife, may act as the source for important pandemic viruses.”
Dr Esther Choo, a physician and professor at the Oregon Health and Science University, quoted a colleague in a tweet – highlighting fears of the disease among scientists.
She said: “From my colleague, an infectious disease specialist, ‘I rarely get worried, but this one bears close watching. This flu strain is very very dangerous’.”
But, there are scientists who believe the strain will not become a pandemic and might never.
Carl Bergstrom, a University of Washington biologist, also posted on Twitter: “There’s no evidence that G4 is circulating in humans, despite five years of extensive exposure. That’s a key context to keep in mind.”
“It is of concern that human infection of G4 virus will further human adaption and increase the risk of a human pandemic.”
The scientists spoke out after a new study has mentioned pigs need to be monitored over fears they could “become intermediate hosts of a future pandemic”.
Animals have been frequently theorised as being carriers of the virus with different studies mentioning pangolins and bats as susceptible.
But now a group of researchers have urged farmers to take particular care with pigs after the preliminary results of a new study found both the animal and cats had cells which are vulnerable to coronavirus.