Prepare bird flu vaccines now before virus jumps to humans, top scientist warns

Governments across the world should urgently organise vaccines and other countermeasures to combat bird flu lest the disease which recently jumped to mammals starts to spread in humans, according to one of the world’s leading scientists.

Sir Jeremy Farrar, a former member of Sage and Chief Scientist designate of the Word Health Organization, said the avian H5N1 virus which is sweeping global bird populations posed the biggest current pandemic threat to the world after Covid.

The recent jump of the virus from birds to mammals, including mink, foxes, otters and sea lions here in Britain and around the world, should be regarded as a claxon call for government action, he added.

“If there was an outbreak in Europe, the Middle East, America or Mexico tomorrow of H5N1 in humans, we wouldn't be able to vaccinate the world within 2023,” said Sir Jeremy at a press briefing in London.

“So what I would like to see [is]...  governments invest in having vaccines for every strain of influenza that exists in the animal kingdom through at least phase one and phase two [clinical trials].”

Sir Jeremy said the investment required to make such vaccines would not be wasted even if the current bird flu pandemic did not jump to humans.

“If there were an H5N1 outbreak [in humans] we would at least know that we had vaccines available, which were safe and effective. And if it doesn't happen, you haven't lost, because you’ve still got those [vaccines].”

Sir Jeremy added that a failure to act now, not just in creating new vaccines but in lowering the risk of the virus jumping to humans by improving biosecurity in farms and markets, could be seen in hindsight as a tragic omission.

“Imagine, tomorrow morning at nine o'clock there’s a report that there’s 100 people admitted to a hospital somewhere with a nasty respiratory virus, and it happens to be H5N1,” he said.

“That’s my concern; that we’re in slow motion watching something which may never happen but if it were to happen, would we look back and say, ‘Why didn’t we do more?’”

Genetic mutations

H5N1 was first reported in the Far East almost 20 years ago and has spread to become common in farmed poultry and wild birds around the world.

Although it does not yet spread efficiently between people, there have been 868 confirmed human cases and 457 deaths due to avian influenza cases reported to the World Health Organisation from 21 countries since 2003.

The fatality rate in humans is estimated to be around 50 per cent, although this varies by country and the exact strain of the virus observed.

What is worrying scientists now is that the virus has spread to affect many more types of bird and mammals.

Further, scientists have observed genetic mutations in the virus which they say may carry “public health implications”.

Sir Jeremy said the progress of H5N1 in the last few years could be characterised as a terrible natural experiment.

“If you wanted …  to create something nasty, you would take a nonhuman influenza virus, you'd let it spread around the world amongst poultry, wild birds, etc,” he said.

“You would let those wild birds and poultry mix with mammals … and then you'd gradually let it go into minx and then maybe foxes and then maybe seals … and maybe dogs and cats.

“And then you'd see a small cluster of human cases somewhere having acquired the evolutionary advantage of mammalian to mammalian transmission.

“And you do that at a global scale, so there’s a shedload of viruses circulating.

“That's what we're doing.”

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