Bird flu is spreading “efficiently” in ferrets, scientists have warned amid growing fears it could spark another pandemic.
Experts called the finding “very concerning”, saying it shows the pathogen is on the verge of spreading to humans.
This is the first known study to clearly confirm that mammals can not only catch the disease individually, but also transmit it to others.
Deaths of infected mammals such as mink, foxes, raccoons and bears in recent months, however, have suggested that it is possible.
H5N1 – the bird flu strain behind the current epidemic sweeping the world, considered the largest of all time – does not transmit easily between humans.
H5N1 – the bird flu strain behind the current epidemic sweeping the world – does not spread easily between humans. But the research, currently being reviewed by the journal Nature, has found that H5N1 could “cause fatal disease in multiple mammalian species” and that “direct contact” between ferrets can lead to “lethal outcomes” ( stock picture)
But mutations in the virus that facilitate mammal-to-mammal transmission could change that, some experts fear.
Globally, fewer than 900 human cases of H5N1, which kills nearly 50% of everyone it strikes, have been recorded.
The virus is usually contracted through close contact with an infected bird, whether dead or alive.
Today, new research, which has not yet been peer reviewed, has found that H5N1 can “cause fatal disease in several species of mammals”.
Canadian researchers, including some from government health agencies, have infected ferrets with one of four strains of H5N1.
Ferrets were chosen for the study because they have a similar respiratory composition to humans, giving experts an idea of how a virus would interact in humans.
They discovered that “direct contact” with a strain of H5N1 isolated from an infected bird led to “lethal consequences”, adds the newspaper.
This raises the possibility that the strain has evolved “certain adaptations that allow a higher degree of replication, pathogenicity and transmission”.
They warned that if such a strain made the jump to humans, the consequences could be catastrophic.
“Because there is little or no population-wide immunity specific to H5, if an H5N1 isolate capable of sustained transmission were species-jumping in humans, it would likely represent a destructive infection in an immunologically naïve population,” they wrote.
John Fulton, pharmaceutical industry consultant and founder of BioNiagara, told MailOnline that H5N1 posed a threat “100 times worse than Covid”.
He added: “This finding is very concerning and governments should take immediate action by identifying and mobilizing all high-potential production capacities of vaccines and therapies for the prevention and treatment of H5N1 avian influenza.”
“We need to sound the alarm to wake up our governments to the fact that there is a virus that is undergoing mutations that could eventually allow it to become highly transmissible in humans (mammals).
“The wake-up call is that we have some of the manufacturing capacity needed to produce cell-based vaccines (no chickens – no eggs) but we need to act now and fund the scale-up we have to cell-based production if we want to be ready if H5N1 mutates further.’
Some countries, including China, have been vaccinating against the H5N1 strain for years.
Some countries, including China, have been vaccinating against the H5N1 strain for years. Birds are vaccinated either by injection into the egg or by spraying the chicks while still in boxes
Under UK health policy, vaccinating chickens is currently illegal. But the Animal and Plant Health Agency, a branch of DEFRA, is currently investigating potential candidate vaccines for humans in the UK, should the virus spread to humans. “The number of laying hens available to produce eggs for vaccine production has already been compromised and is vulnerable to a complete destruction of the egg producing flock, leaving us with limited production capacity,” Mr Fulton said.
Birds are vaccinated either by injection into the egg or by spraying the chicks while still in boxes.
Under UK health policy, vaccinating chickens is currently illegal.
But the Animal and Plant Health Agency, a branch of DEFRA, is currently investigating potential candidate vaccines for humans in the UK, should the virus spread to humans.
“The number of laying hens available to produce eggs for vaccine production has already been compromised and is vulnerable to a complete destruction of the egg producing flock, leaving us with limited production capacity,” Mr. Fulton.
Vaccine makers GSK, Moderna and CSL Seqirus have begun developing new human vaccines to target the rapidly spreading strain of the virus.
Others like Sanofi have generic vaccines against the H5N1 virus in stock that could be adapted to the strain currently in circulation.
Like other forms of influenza, humans can become infected if the virus gets into their eyes, nose, mouth, or is inhaled.
But with bird flu, it usually happens in people who spend a lot of time with infected creatures, like bird trainers.
A wave of human cases of bird flu emerged in early 2023.
Earlier this year, a Cambodian man and his daughter were diagnosed with H5N1.
Their cases have sparked international concern, with many experts fearing the infection is proof that the virus has mutated to better infect people after ripping apart the world’s bird population.
Further testing revealed that the Cambodian family did not have the H5N1 strain spreading rapidly among the world’s wild birds – but rather a variant known to spread locally in the Prey Veng province in which they resided.
There has been only one case of a Briton being infected with H5N1 since the ongoing outbreak began in October 2021.
Alan Gosling, a retired engineer from Devon, caught the virus in early 2022 after his ducks, some of which lived inside his house, became infected.
The UK Health Security Agency (UKHSA) has currently set the threat level at level three as there is ‘evidence’ of changes to the virus genome which could trigger ‘mammalian infection’, a- she declared.
Any “sustained” mammal-to-mammal transmission of the pathogen would raise the threat level to four, while human-to-human would raise it to five.