WHAT WAS CLAIMED
Birds can't get flu and don't transmit it.
OUR VERDICT
False. Many strains of avian influenza have been documented globally and are highly contagious.
AAP FACTCHECK - Birds can get flu, they can sneeze, and the viruses they contract are contagious, contrary to false claims being made by a British vaccine sceptic.
Experts say more than a dozen strains of avian influenza have been studied extensively, while data shows hundreds of confirmed cases of human transmission.
Additionally, respiratory symptoms, including coughing and sneezing, have been seen in birds with viral infections and are cited in numerous academic publications.
The false claims appear in a Facebook video posted on July 5, 2025, featuring former Pfizer executive Michael Yeadon stating that birds cannot get the flu. "Have you ever seen a chicken with a cold? Have you ever seen them coughing or sneezing?" he asks in the video.
"Birds do not get influenza. They don't."
He goes on to claim that polymerase chain reaction (PCR) tests used to detect avian influenza are "fraudulent" and used to justify the killing of bird flocks.
"They're lying to you about these illnesses. Birds can get sick but they haven't got flu and it's not contagious," Dr Yeadon says.
When contacted by AAP FactCheck, Dr Yeadon expanded on his view, claiming that there is no bird flu or avian influenza because there is no evidence that viruses exist.
"The entire field, which is surprisingly young, is fraudulent. Obviously, animals including & (sic) birds can develop illnesses. However, and this is crucial, such illnesses are deliberately & systematically misattributed to 'viruses'," he wrote in an email response. "Birds do not 'catch influenza' because the alleged pathogenic principal, an influenza virus, is entirely fraudulent."
Dr Yeadon went on to claim that scientists had yet to show the "symptomatic transmission of such illnesses from a sick person to a well person" in a century of clinical experimentation.
Virology and veterinary science experts told AAP FactCheck that each of Dr Yeadon's claims is false.
Edward Holmes, a virologist at the University of Sydney, said scientific studies have shown that viruses exist and have the ability to transmit. "Influenza viruses have been repeatedly isolated, grown and sequenced from a diverse array of animals including humans and birds," Professor Holmes told AAP FactCheck. "Numerous experimental infections have shown that birds, such as chickens, can be infected with influenza virus and develop disease, which is sometimes fatal."
Scientists have been imaging viruses for more than half a century using electron microscopy, which was first established in the 1930s, according to the journal Clinical Microbiology Reviews.
It has since been used to develop methodology for the classification of viruses, according to the Canadian Medical Association Journal.
Other laboratory methods isolate and cultivate viruses for observation, including PCR testing, which Dr Yeadon describes as "fraudulent". AAP FactCheck has previously debunked claims bird flu is a fraud because PCR tests are unreliable, with experts saying they are highly accurate when used appropriately.
PCR tests work by selectively amplifying genetic markers within a virus to the point a particular strain can be identified.
To achieve this, the test uses a reaction that creates copies of the virus repeatedly, increasing exponentially with each "cycle".
The Journal of Infection published a 2022 paper demonstrating a methodology for evaluating the transmission of respiratory viruses using PCR testing of volunteers.
The study observed interactions between infected children displaying respiratory symptoms and healthy adults in a clinical setting, demonstrating transmission.
Prof Holmes said that there have been numerous experimental infections of respiratory viruses involving human volunteers, as well as real-world analyses.
"Every day many thousands of people develop respiratory illnesses caused by viruses," he said.
"There's likely not a single household globally that hasn't experienced a family member becoming sick with a respiratory illness, with other family members then becoming sick a few days later."
Wayne Boardman, a veterinarian at the University of Adelaide, said bird flu exhibits clinical signs and is contagious, adding that PCR diagnostic tests are an accurate method for diagnosing avian influenza.
"The claims are inaccurate," Associate Professor Boardman said.
Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in the US, who has authored papers on bird flu, said the disease has been extensively documented.
"Of course there is bird flu," he told AAP FactCheck.
He said there are 16 subtypes of influenza virus known to circulate in birds and "several of them can be highly pathogenic".
The global spread of bird flu, including hundreds of cases of human transmission, has been documented since it was first identified in 1959, according to a 2023 scientific review published in Travel Medicine and Infectious Disease.
Between 2003 and 2024, a total of 939 confirmed cases of the highly pathogenic avian influenza A(H5N1) were recorded, according to the World Health Organization.
The US Centers for Disease Control reported that the current outbreak was first detected in bird populations in North America in 2022.
The virus spread to dairy cows as well as at least 40 humans between March and October 2024, according to a paper in the New England Journal of Medicine.
Birds have also displayed respiratory symptoms as a result of bird flu infections, including coughing and sneezing, according to a study published in Veterinary World.
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