Multiple researchers have responded to the CDC’s findings.
A genetic analysis suggests the bird flu virus mutated inside a Louisiana patient who contracted the nation’s first severe case of the illness, federal health officials said this week.
The U.S. Centers for Disease Control and Prevention (CDC) said its researchers compared viruses obtained from the Louisiana case to a virus that came from infected birds on the patient’s property.
The CDC said changes seen in the person were not present in the virus samples obtained from the birds, suggesting that mutations developed during the person’s infection.
“The changes observed were likely generated by replication of this virus in the patient with advanced disease rather than primarily transmitted at the time of infection,” the CDC report said.
What Researchers Say
Michael Osterholm, a University of Minnesota infectious disease researcher, likened this binding interaction to a lock and key. To enter a cell, the virus needs to have a key that turns the lock, and this finding means the virus may be changing to have a key that might work.
“Is this an indication that we may be closer to seeing a readily transmitted virus between people? No,” Osterholm said. “Right now, this is a key that sits in the lock, but it doesn’t open the door.”
Angela Rasmussen, a virologist who specializes in infectious diseases, wrote that “more [genetic] sequences from humans is a trend we need to reverse” and that “we need fewer humans infected” by bird flu.
“We don’t know what combination of mutations would lead to a pandemic H5N1 virus, and there’s only so much we can predict from these sequence data. But the more humans are infected, the more chances a pandemic virus will emerge,” wrote Rasmussen, who works at the University of Saskatchewan’s Vaccine and Infectious Disease Organization, on social media platform X.
She said the Louisiana “patient was infected by the birds, but because the bird viruses don’t have these sequences, it’s likely they emerged in the human host,” which she called “good news.”
“It reduces the risk of transmission to another person and suggests ‘human-adapted’ viruses aren’t emerging in birds,” Rasmussen said.
