A human outbreak of bird flu is imminent and could cause death and devastation across the world – here top doctors reveal how YOU can protect yourself… and the warning signs to watch out for

For 30 years now, scientists have worried about the possibility of a human outbreak of bird flu. Today, however, many experts believe we’re closer than ever to a new pandemic. But the big question is this: are we prepared?

A ‘highly pathogenic’ strain of bird flu, known as H5N1, is already spreading rapidly through chicken and wild bird populations, and if it were to mutate and spread into humans, it would be the kind of flu strain that most people would have no immunity against.

Many fear it could, in a worst-case scenario, be both virulent and transmissible enough to cause a wave of deaths and serious illness across huge swathes of the global population.

The first human death linked to this strain of bird flu was reported earlier this month – a man in Louisiana, in the US, who caught it from a backyard flock.

Since 2003, the World Health Organisation has confirmed 954 human cases linked to other strains, of which around half have died.

And this week, a patient in the Midlands was also diagnosed with the virus after ‘close and prolonged contact with a large number of infected birds’. It is the seventh case in the UK since 2021.

While it is thought to be an isolated incident, health officials raised concerns over a ‘growing number of avian flu cases in birds on both commercial farms and in backyard flocks across the country’.

Crucially, those who have become infected have not – so far – generally been able to pass it on to other people. That, however, could change.

Flu viruses mutate all the time, and the concern from scientists and government officials is that a strain of the virus, passed to humans from chickens or from another animal, could develop the capability of spreading between humans.

This week, a patient in the Midlands was also diagnosed with H5N1 after ‘close and prolonged contact with a large number of infected birds’

Many say this is a case of when – not if – it happens. So what, then, might an outbreak look like?

Today, the Mail recruits some of the country’s leading virologists, epidemiologists and pandemic planners to imagine the kind of scenario that might unfold in the UK – and how best to protect yourself if it does…

Week one

Scientists from the Animal and Plant Health Agency (APHA), which scans for new threats from highly-pathogenic avian influenza, pick up another outbreak of H5N1 bird flu at a poultry farm in Yorkshire.

It’s the 25th outbreak since November 2024, and is the same strain which has spread to, and killed, thousands of wild birds including geese, ducks, swans and gulls. It has also spread to farmed mink in Spain and sea lions in Peru.

Monitoring and surveillance in the UK has been ramped up in response to the potential threat.

The Yorkshire flock are slaughtered and a 3km protection zone put in place – anyone within it must keep commercial or backyard flocks housed to protect them. A 10km surveillance zone around the premises allows scientists to monitor any spread into the wild bird population.

The strain is sent to the laboratory for genomic sequencing – a detailed analysis of its DNA to see whether it has mutations which might make it more easily transmittable to humans. It can also be compared to other known strains circulating worldwide.

Meanwhile, the UKHSA, which already routinely tests poultry farm workers for bird flu, increases testing and surveillance for those who work at the Yorkshire premises.

The infection has, however, already passed to wild ducks. They have been congregating on a pond in a field used by dairy cattle, where their droppings – which carry the infection – enter the water.

Virologists say the virus can linger in water, and as the dairy herd drinks from the pond, they pick up the infection themselves.

A similar situation has caused outbreaks of bird flu in cows in the US, which infected workers at dairy farms.

No cattle have been found to have the virus in the UK – but scientists agree that jump is ‘plausible’.

The APHA and the cattle industry have been carrying out surveillance on UK cows because of this risk, and new laws allow them to investigate dairy cattle held close to infected poultry. But there is currently no routine monitoring on dairy farms or their workers.

Dr Richard Pebody, director of clinical and emerging infections at the UKHSA, says there are many systems in place to ‘hopefully try and pick things up at as early a stage as possible’ but agreed it wasn’t possible to ‘put plugs everywhere’.

Week two

A worker at the dairy farm develops symptoms of flu. It’s fairly mild – a few days of a high temperature and feeling under the weather – and he passes it to his wife, a receptionist at the local GP practice.

She is sent home to recuperate, but not before she has spread the virus to a couple of elderly patients, and to other members of staff. One of the nurses who picks up the virus has children at the local primary school, who themselves later develop symptoms which they unknowingly spread to their classmates.

Professor Ian Brown, avian virology group lead at the Pirbright Institute, which is closely monitoring bird flu viruses as they emerge to check whether they’re changing, says: ‘When people are diagnosed with bird flu, there is a very rapid response system in place to identify all of their close contacts.

‘But the problem is the lag in initiating that trigger system. If you had a slow burner, someone who didn’t get particularly sick but they still passed on the virus, it could spread to a few people before it gets to someone who’s sick enough to need hospitalisation where they’ll be tested. As we saw with Covid, you could get a rapid escalation of an outbreak.’

Week three

At a busy hospital in Yorkshire, 20 miles from the dairy farm, a respiratory specialist is concerned about the ten patients she has in ICU. A further four children are in paediatric intensive care.

Tests when they were admitted reveal all have a flu virus, but it appears to be more severe than the other seasonal flu cases she’s seen so far this year.

For a start, some of the patients are otherwise healthy adults in their 40s who have developed something she remembers from the Covid pandemic – a ‘cytokine storm’, in which the body’s immune system over-reacts to the virus it’s fighting, causing respiratory distress and damage to other organs.

‘In the past, highly-pathogenic strains of influenza have been unusual in triggering this kind of response in healthy adults,’ says Professor Hutchinson. ‘We saw it in the 1918 pandemic, and sporadically in severe human cases of H5N1.

The first human death linked to H5N1 was reported earlier this month – a man in Louisiana who caught it from a backyard flock

‘In the 400-odd people who died of H5N1 prior to 2020, this was the sort of disease they were experiencing.’

Meanwhile, several nurses in ICU, and one consultant in A&E where the patients were first brought in, have come down with flu.

The respiratory consultant reports the unusual cluster of cases to local public health officials, who contact the UKHSA.

Week four

More extensive tests on the patients and healthcare workers reveal all are suffering from the same novel strain of H5N1.

Genomic sequencing suggests the virus has mutated and is the same strain spreading between humans in parts of Germany, Argentina and the US. There are whispers on social media about a strange new bug.

Professor Sir Peter Horby, director of the Pandemic Sciences Institute at the University of Oxford and former chairman of NERVTAG, which advises the Government on the threat posed by new respiratory viruses, says: ‘Once it’s been confirmed as an avian flu virus, alarm bells would ring straight away.

‘Officials will want to see if they can join the dots between the cases – is this something spreading just between this group of people or is it spreading more widely?

‘If you have ten severe cases and a lot of missing links between them, that’s the tip of a much bigger iceberg.’

Officials trace their contacts, who will also be interviewed and tested for symptomatic or asymptomatic infection.

They could also be asked to quarantine in their own homes and be monitored for signs of infection.

Any close contacts deemed to be particularly vulnerable to flu – the elderly, those with a compromised immune system or children – could be given antiviral drugs to take, such as oseltamivir or zanamivir. These may reduce the severity of symptoms and help prevent onward transmission.

The Government has a stockpile of these antivirals, but will not confirm how much it has – only that it is kept ‘under review and informed by expert advice to ensure sufficient stock is in place’.

If the outbreak is deemed to be just a cluster in a particular town, with no evidence of onward spread and close links between them, ‘you might consider a local mass vaccination programme’, says Professor Horby.

The Government announced last month it had ordered five million doses of a vaccine against an H5 strain from UK-based company, CSL Seqirus UK Limited. The company already produces the UK’s seasonal flu vaccines.

Dr Meera Chand, emerging infection lead at the UKHSA, said the vaccine would be used ‘if this virus were to start spreading among humans’.

Unfortunately, it’s too late to contain the outbreak – new cases are popping up in hospitals from Plymouth to Inverness.

Week five

The first patient in the UK dies of bird flu – an elderly man, who is reported to have multiple underlying health conditions.

NERVTAG and the Scientific Advisory Group for Emergencies, known as SAGE, meet and discuss how best for the Government to communicate the risk.

However, experts say compulsory measures to control the virus like lockdowns and social-distancing are highly unlikely.

Professor Sir Chris Whitty told the Covid Inquiry the Government ‘overdid’ warnings at the start of the pandemic – so bird flu communications would be likely to involve less doom-mongering

‘It’s unlikely people would follow such rules now,’ says Professor Horby. ‘But it’s not Covid – it’ll be less transmissible than Covid, as all flu strains are, and we have vaccines and antivirals which will offer some protection and reduce transmission.’

The Government’s chief medical officer, Professor Sir Chris Whitty, also told the Covid Inquiry that the Government ‘overdid’ warnings at the start of the pandemic – so the likelihood is the approach would involve less doom-mongering.

Prime Minister Sir Keir Starmer calls a press conference to announce the death, flanked by a senior UKHSA official and Professor Whitty.

They announce that the novel bird flu virus is spreading within communities in the UK, and that early data from modellers suggests it could lead to 65,000 deaths in a ‘worst case scenario’. This is twice the number of deaths from a bad seasonal flu year.

They also point out that similar predictions were made about deaths during the H1N1 swine flu pandemic in 2009, when the eventual total was just 457.

It announces that its existing vaccine stockpile is being offered to NHS staff, farm workers and the most vulnerable – the elderly and those with compromised immune systems – to curb the spread in virus hotspots.

Critics point out there isn’t enough to go round to immunise all the ‘vulnerable and valuable’ across the country – you’d need at least 15million doses for those groups alone.

‘While five million doses isn’t enough to control a widespread outbreak, it could provide a good start through vaccinating groups exposed in the early stages of an outbreak, particularly healthcare workers and farm workers,’ says Professor Hutchinson.

The Government also says it has a ‘stockpile’ of lateral flow tests (LFTs), nasal and throat swab tests which can pick up flu (similar versions were used during the Covid pandemic). However, officials won’t say how many the UK has in stock.

These LFTs can pick up the two main types of flu – influenza A and influenza B – and will pick up bird flu because it is a strain of influenza A. Such tests are already available to buy online or from high street pharmacies.

Those testing positive could be asked to stay at home and to register the infection on a (hypothetical) bird flu app – a reconfigured version of the Covid app, which could alert recent contacts that they may have been exposed to the virus. They will also get antivirals sent to them.

It’s unlikely the £37billion NHS Test and Trace scheme – which saw potentially infected Britons contacted and ordered to isolate – would be resurrected after it was found to be ‘muddled, overstated, and eye-wateringly expensive’.

Professor Whitty recommends those who want to wear masks should do so, and advises vulnerable people to avoid crowded places.

The Government announces it has also asked CSL Seqirus to provide a further 50million doses of a new bird flu vaccine based on the exact strain of the circulating virus.

It has an advance contract for such an event – but getting it ready and rolling it out might take ‘between four and six months’, based on previous experience, suggests Dr Pebody.

Week six

Nearly 300,000 people have seen their GP for flu-like symptoms in the past week, which means the virus has officially reached ‘epidemic’ proportions in the UK.

Hospitals across the country are now declaring critical incidents because of ‘exceptionally high demand’ in A&E, and on critical care and intensive care wards.

Unfortunately, despite capacity being stretched during Covid, with fewer ICU beds than other wealthy nations, this issue has still not been addressed.

But unlike Covid, people will be clearly told that hospitals are still open for non-flu treatment – Professor Whitty told the Covid Inquiry that the Government ‘didn’t get [this] across well enough’.

The Government has refused to disclose details of its PPE stockpile so it’s unclear whether the UK is in a better position to protect healthcare workers.

‘I don’t think bed numbers or staffing are any better than it was in 2020,’ says Professor Horby. ‘But what has changed is our understanding of the feasibility of home-based testing with LFTs and isolating at home to keep people out of hospital.’

There are stockpiles of antibiotics to treat secondary complications such as pneumonia, the Government says.

Corticosteroids such as dexamethasone, which dampens down the body’s inflammatory response to infection, could also play a role.

Meanwhile, since officials confirmed the likely source of the outbreak was a dairy farm, sales of beef and chicken have plummeted, with fake news spreading on social media that people can become infected by eating the meats. There were similar concerns during the swine flu pandemic of 2009, which caused pork sales to fall in some parts of the world.

Public health experts and the Food Standards Agency wade in to correct the ‘misinformation’ and reassure the population that the virus cannot spread into humans by eating beef or chicken.

Week seven

Several schools are badly affected, with children asked to learn remotely in some cases because of teacher absences. Some classes also have so many children off with flu that the others are asked to home school.

Experts say that school closures in the event of H5N1 will be unlikely – even though, ironically, flu is likely to affect children more severely than Covid.

Dame Sally Davies, the former chief medical officer, told the Covid Inquiry that lockdown measures had ‘damaged a generation’ while Rishi Sunak also said he’d argued for schools to remain open.

Meanwhile, people have noticed their cats becoming ill. Bird flu is known to be severe in cats – a ten-week-old kitten died in Iceland earlier this month, and 20 big cats including a Bengal tiger and four cougars have died of bird flu in a zoo in Washington state, in the US.

Could this be a devastating epidemic for the nation’s felines? Sometimes, animals are culled to protect humans – during Covid, Denmark culled 17million mink when a form of the virus that could spread to humans was found.

But experts say the risk of catching bird flu from your cat is ‘very low’, which means – on the current evidence, at least – a cat cull isn’t likely to be on the cards.

Week eight

How bad could it get? Some experts say in a worst-case scenario we could see a pandemic that rivals the Great Influenza epidemic of 1918. That virus affected one fifth of the world population, and killed an estimated 50million people.

But not all novel flu viruses are so dangerous. In 2009, for example, officials warned the H1N1 swine flu pandemic could cause 65,000 deaths in the UK – in the end, 457 people died.

It won’t be clear how serious a bird flu pandemic could be until it arrives. What matters is the case fatality rate – how many people die after being infected – and how easily it spreads.

MERS, a type of coronavirus that appeared in the Middle East in 2012, kills 35 per cent of those infected – around one in three. But it doesn’t pass easily between people, so has ultimately led to fewer than 1,000 deaths.

Covid, meanwhile, had a much lower case fatality rate. The original Alpha strain killed 2.62 per cent of those it infected. However, because it could spread swiftly it infected more than 700million people, killing seven million.

In general, flu doesn’t spread as easily as Covid. But as epidemiologist Professor Mark Woolhouse from the University of Edinburgh explains: ‘The worst-case scenario is we get a strain that combines the virulence of some of the bird flus with the transmissibility of some of the human flus. That has been the concern for 30 years.

‘If it’s a very visible, severe infection then it should be easier to contain if we throw all the contact tracing capability we have at it.

‘If it moves fast and less visibly within the population, containing it will be harder so we may see more deaths and serious illness overall, even if the symptoms are milder for most people.’