Scientists believe they have identified a gene that stops humans from becoming infected with bird flu viruses.

Known as BTN3A3, this gene is expressed in the airways and has been shown in the lab to stop avian flu viruses from spreading by making copies of itself.

The researchers said that their work, published in the journal Nature, could help identify new and emerging viruses that have the potential to cause a pandemic.

Prof Massimo Palmarini, the director of the MRC-University of Glasgow Centre for Virus Research, who led the study, said: “We know that most emerging viruses with human pandemic potential come from animals.

“It is therefore critical to understand which genetic barriers might block an animal virus from replicating in human cells, thereby preventing infection.

“Of course, viruses are constantly changing and can potentially overcome some of these barriers by mutating over time.”