Scientists have identified another emerging flu virus in China that poses "the risk of a human pandemic", while the world continues to battle the coronavirus outbreak.
Yesterday the global total of Covid-19 cases topped 10 million and the global death toll reached 500,000.
The new virus is similar to the H1N1 swine flu which swept the world in 2009, according to the paper published today in the journal PNAS.
However unlike the swine flu, the current influenza vaccine doesn't appear to cover the newly identified virus G4 EA H1N1 and people don't have immunity for it - although the flu vaccine could be adapted if necessary.
"It is of concern that human infection of G4 virus will further human adaptation and increase the risk of a human pandemic," the scientists say.
"Epidemiological survey found that the two patients had neighbours who reared pigs, suggesting that G4 EA virus could transmit from swine to human, and lead to severe infection and even death."
In the paper, the scientists say 10.4 per cent of swine workers tested (35 of 338) were found to have antibodies for the virus, "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," the scientists say.
While it's not known how severe the virus is or whether it could become as widespread as the coronavirus, the researchers warn that it's something that needs to be watched.
"Controlling the prevailing G4 EA H1N1 viruses in pigs and close monitoring in human populations, especially the workers in [the] swine industry, should be urgently implemented."