It’s a story that may not have garnered much notice a scant six months ago: Chinese scientists have identified a strain of influenza in pigs that has “all the hallmarks” of a potential human pandemic. But in the wake of a novel strain of coronavirus that has shut down much of the global economy and killed over 500,000 worldwide such a report is prone to capture a little more attention.
On Monday, a study published in the Proceedings of the National Academy of Sciences journal by researchers in China noted that a strain of the flu that has been “predominant in swine populations since 2016” has “all the essential hallmarks of a candidate pandemic virus.” Researchers are concerned that a further mutation would allow the virus to transmit more easily between people, while the BBC notes that the researchers “found evidence of recent infection starting in people who worked in abattoirs and the swine industry in China.”
The study took place from 2011 to 2018, involving around 30,000 swabs from pigs in slaughterhouses in ten Chinese provinces; a total of 179 virus strains were found among the swine, including the worrisome flu strain they have identified as G4 EA H1N1. As Business Insider notes, “The virus is a combination of three flu strains … one from European and Asian birds, the flu strain that caused the 2009 swine flu outbreak, and a North American flu that has genes from bird, human, and pig flu viruses.” The virus appears to be able to grow in cells lining the airways in humans, and because it bears a similarity to the strain of H1N1 flu that killed hundreds of thousands globally in 2009, it “may promote the virus adaptation” that results in human-to-human transmission.
The researchers also wrote that the virus “is “distinct from current human influenza vaccine strains, indicating that preexisting immunity derived from the present human seasonal influenza vaccines cannot provide protection.” However, they also note that the current flu vaccine — a quadrivalent shot designed to provide protection against four separate virus strains — could be adapted for the new flu. To reduce the risk of potential spread, the researchers called for new efforts to control “the prevailing G4 EA H1N1 viruses in pigs,” and “close monitoring in human populations, especially the workers in swine industry, should be urgently implemented.”
Meanwhile, Dr. Anne Schuchat, the principal deputy director of the Centers for Disease Control and Prevention, warned on Monday that the United States has “way too much virus” to be able to control the current pandemic. Also on Monday, Tedros Adhanom Ghebreyesus, director general of the World Health Organization, cautioned that “the worst” of the coronavirus “is yet to come.”