China on Wednesday played down the threat of a new swine flu strain with pandemic potential that researchers discovered in pigs, saying the study is "not representative".
The deadly COVID-19 pandemic, which has now infected more than 10 million people worldwide, first emerged in China and is thought to have originated in bats and jumped to humans through an unknown intermediary animal.
The new swine flu strain found in China, according to the study published Monday in the US science journal PNAS, had "all the essential hallmarks" to infect humans and raised fears over another potential pandemic.
But China's foreign ministry moved to downplay fears on Wednesday.
"The G4 virus mentioned in the relevant report is a subtype of the H1N1 virus," foreign ministry spokesman Zhao Lijian said in a routine briefing.
"Experts have concluded that the sample size of the report is small and not representative."
Zhao added that "relevant departments and experts" will continue to step up monitoring of the disease, send warnings and handle it in a timely manner.
The new G4 swine flu strain is genetically descended from the H1N1 strain that caused a pandemic in 2009, according to the study, which was authored by scientists at Chinese universities and the Chinese Center for Disease Control and Prevention.
G4 was observed to be highly infectious, they said, replicating in human cells and causing more serious symptoms in ferrets than other viruses.
Researchers took 30,000 nasal swabs from slaughterhouse pigs in 10 Chinese provinces, allowing them to isolate 179 swine flu viruses.
According to the study, 10.4 percent of pig slaughterhouse workers tested had already been infected.
So far, there has been no evidence of human-to-human transmission. China did not elaborate further on how many had been infected by G4.
"It is of concern that human infection of G4 virus will further human adaptation and increase the risk of a human pandemic," the researchers wrote, calling for urgent measures to monitor people working with pigs.