Bird flu is changing very fast: Health experts warn after first human death in America
Scientists have said that this strain has developed changes that make it better able to spread, cause inflammation and cause severe disease.
Scientists have sounded alarm after the first H5N1 death in the US was reported in January 2025 after exposure to infected chickens.
Researchers have identified nine mutations in the strain of bird flu found in another infected person in Texas, US.
This strain has shown a high ability to cause disease, with a high ability to replicate in the brain. However, the good news is that existing antiviral treatments are still effective against this strain.
Researchers at the Texas Biomedical Research Institute (Texas BioMed) published their detailed findings in the journal Emerging Microbes and Infections. After experiments on mice, they revealed that the new strain had become quite efficient at replicating in human cells, causing severe disease, and was found in very high concentrations in brain tissue.
This strain was compared to the strain found in dairy cattle, which is wreaking havoc in America, Britain and many countries.
“There are nine mutations in the human breed that were not present in the bovine (cattle) breed, which suggests they occurred after human infection,” Dr. Martínez-Sobrido said.
The study showed that the strain, known as rHPhTX, had evolved changes that made it better able to spread, cause inflammation and cause disease in mice.
According to the authors, these changes may increase the risk of the virus spreading among humans. Initially, bird flu was not transmitted to humans, but only to animals.
“As a result, human H5N1 strains should be closely monitored and their public health risk evaluated, and efforts should be made to eliminate H5N1 from cows, to prevent human H5N1 infection by these already mammalian-adapted H5N1 viruses.” can be avoided.” The authors wrote in the study.
The researchers also tested several antiviral drugs approved by the US Food and Drug Administration (FDA) on both virus strains in cells and found that the mutations did not affect the sensitivity of the antivirals.
This means that existing drugs are effective against the mutation of the H5N1 strain.
He said the antivirals could be the first line of defense against bird flu in humans before vaccines become widely available. Another study published in December 2024 showed that antiviral drugs could help because humans have no immunity against H5N1 and seasonal flu vaccines offer limited protection.
