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H5N1 virus mutating in humans, study finds
The human strain of H5N1 caused a more severe disease than the bovine strain.
Research found nine additional mutations in the human strain.

A study into the spread of H5N1 in the United States of America has revealed that the virus has developed new mutations in human hosts.

Researchers from Texas Biomedical Research Institute (Texas Biomed) identified nine additional mutations in the human strain of H5N1 compared to the strain present in bovines.

H5N1, commonly known as bird flu, is naturally found in wild birds and is lethal in chickens. It has since spread through a variety of mammals, first being identified in dairy cows in spring 2024.

The first reported death caused by H5N1 was reported in January 2025, as a result of exposure to infected chickens.

Researchers are increasingly concerned about the evolution of the virus, particularly of its potential to transmit from human to human. Texas Biomed has been studying H5N1 since the outbreak began last year, using specialised tools and animal models.

When comparing the human strain of H5N1 to the strain in bovines, researchers identified nine additional mutations which were believed to have occurred after human infection.

The study found that the human strain of H5N1 caused a more severe disease than the bovine strain. The human strain also replicated more efficiently and was found in much higher quantities in brain tissue.

However, the researchers did also identify that the mutations were not affecting the efficacy of approved antibiotics.

The researchers say that this is an important finding, as antibiotics will be vital if a pandemic does occur. Humans have no pre-existing immunity against H5N1, and seasonal flu vaccines offer limited protection.

Future research will see the team explore the human strain individually, investigating why infections from cows appear to be less harmful than from chickens. They will also examine why H5N1 causes mild disease in cows, but is lethal in cats.

Ahmed Mostafa Elsayed, staff scientist at Texas Biomed, said: "A key priority will be to eradicate bird flu from dairy cows to minimize risk of mutations and transmission to people and other species,

"Steps that can be taken now include thorough decontamination of milking equipment and more stringent quarantine requirements, which will help eliminate the virus more quickly in cows."

The full study can be found in the journal Emerging Microbes and Infections.

Image © Shutterstock

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Applications open for MMI research grants

News Story 1
 RCVS' Mind Matters Initiative (MMI) has launched round two of its veterinary mental health research grants.

Researchers have until 11.59pm on Wednesday, 28 May 2025 to apply for a grant for research which reflects MMI's 2025 focus areas.

Only one Impact Grant was awarded last year, and so this year there are two Discovery Grants and one Impact Grants available. Each Discovery Grant is worth £5,000 and the Impact Grant is worth £15,000.

For more information or to apply, email researchgrants@rcvs.org.uk to contact the MMI team.

 

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Germany livestock import ban lifted

The UK government has amended its ban on the import of livestock, meat and dairy products from Germany.

Defra said the decision follows 'rigorous technical assessment' of the measures applied and the current situation. "If the situation changes, we will not hesitate to take necessary action in response to the FMD outbreaks in the European Union to protect our domestic biosecurity," it said.

The ban was implemented in January following an outbreak of foot and mouth disease (FMD) near Berlin. Personal imports of meat, milk and dairy products will remain in place at a country level.