One Mutation Could Make H5N1 a Greater Threat, Researchers Say

While there has been no sign of person-to-person spread of bird flu, researchers said on Thursday that a single mutation in the H5N1 avian influenza virus could enhance the virus’ ability to attach to human cells. That could potentially increase the possibility of transmission among humans, said the study, led by a team of scientists at the Scripps Research Institute.

“These findings highlight the need for continuous surveillance of emerging mutations in avian and bovine clade 2.3.4.4b H5N1 viruses,” said the study, published in the journal Science. An editor’s summary attached to the study said, “In nature, the occurrence of this single mutation could be an indicator of a human pandemic risk.”

Public health officials say genomic analyses of the H5N1 virus have found no changes that would make the virus more communicable among humans. They say the risk to the general public is low, and advise people to wear protective gear, such as masks and gloves, if they have contact with infected or potentially infected animals. There have been 58 human cases of bird flu in the United States this year. All but two were among livestock workers, and all were mild.

Avian flu viruses rarely adapt to humans and typically require several mutations when they do, said the researchers. However, they said, a single amino acid mutation in hemagglutinin, a protein that binds viruses to receptors on host cells, would allow the bird flu virus circulating among cattle to attach to human-like receptors.

The Scripps scientists said the study demonstrated that the virus could easily evolve to recognize human-type receptors, but it did not suggest that the current H5N1 virus would be transmissible among humans if it acquired the mutation.

Also on Thursday, the California agriculture department said that with 11 new outbreaks identified, 504 dairy herds in the state have been infected with the bird flu virus since it was detected there in late August. There are roughly 1,100 dairy herds in California.

And the chief executive of Raw Farm, which has recalled its unpasteurized whole milk and cream products because they might contain the bird flu virus, told the Los Angeles Times that he has applied for the position of “FDA adviser on raw milk policy and standards development” in the incoming Trump administration. Mark McAfee said he was encouraged to apply for a position at the FDA by the transition team for Robert F. Kennedy, nominated by President-elect Donald Trump to head the Department of Health and Human Services.