For 30 years now, scientists have apprehensive about the potential of a human outbreak of hen flu. At present, nonetheless, many specialists imagine we’re nearer than ever to a brand new pandemic. However the massive query is that this: are we ready?
A ‘extremely pathogenic’ pressure of hen flu, generally known as H5N1, is already spreading quickly by rooster and wild hen populations, and if it had been to mutate and unfold into people, it might be the sort of flu pressure that most individuals would haven’t any immunity towards.
Many worry it might, in a worst-case situation, be each virulent and transmissible sufficient to trigger a wave of deaths and severe sickness throughout big swathes of the worldwide inhabitants.
The primary human demise linked to this pressure of hen flu was reported earlier this month – a person in Louisiana, within the US, who caught it from a yard flock.
Since 2003, the World Well being Organisation has confirmed 954 human instances linked to different strains, of which round half have died.
And this week, a affected person within the Midlands was additionally identified with the virus after ‘shut and extended contact with numerous contaminated birds’. It’s the seventh case within the UK since 2021.
Whereas it’s regarded as an remoted incident, well being officers raised considerations over a ‘rising variety of avian flu instances in birds on each industrial farms and in yard flocks throughout the nation’.
Crucially, those that have develop into contaminated haven’t – up to now – usually been capable of cross it on to different folks. That, nonetheless, might change.
Flu viruses mutate on a regular basis, and the priority from scientists and authorities officers is {that a} pressure of the virus, handed to people from chickens or from one other animal, might develop the aptitude of spreading between people.
This week, a affected person within the Midlands was additionally identified with H5N1 after ‘shut and extended contact with numerous contaminated birds’
Many say it is a case of when – not if – it occurs. So what, then, would possibly an outbreak appear like?
At present, the Mail recruits among the nation’s main virologists, epidemiologists and pandemic planners to think about the sort of situation that may unfold within the UK – and the way greatest to guard your self if it does…
Week one
Scientists from the Animal and Plant Well being Company (APHA), which scans for brand spanking new threats from highly-pathogenic avian influenza, choose up one other outbreak of H5N1 hen flu at a poultry farm in Yorkshire.
It’s the twenty fifth outbreak since November 2024, and is similar pressure which has unfold to, and killed, hundreds of untamed birds together with geese, geese, swans and gulls. It has additionally unfold to farmed mink in Spain and sea lions in Peru.
Monitoring and surveillance within the UK has been ramped up in response to the potential risk.
The Yorkshire flock are slaughtered and a 3km safety zone put in place – anybody inside it should hold industrial or yard flocks housed to guard them. A 10km surveillance zone across the premises permits scientists to watch any unfold into the wild hen inhabitants.
The pressure is distributed to the laboratory for genomic sequencing – an in depth evaluation of its DNA to see whether or not it has mutations which could make it extra simply transmittable to people. It may also be in comparison with different identified strains circulating worldwide.
In the meantime, the UKHSA, which already routinely assessments poultry farm employees for hen flu, will increase testing and surveillance for individuals who work on the Yorkshire premises.
The an infection has, nonetheless, already handed to wild geese. They’ve been congregating on a pond in a subject utilized by dairy cattle, the place their droppings – which carry the an infection – enter the water.
Virologists say the virus can linger in water, and because the dairy herd drinks from the pond, they choose up the an infection themselves.
An analogous scenario has induced outbreaks of hen flu in cows within the US, which contaminated employees at dairy farms.
No cattle have been discovered to have the virus within the UK – however scientists agree that soar is ‘believable’.
The APHA and the cattle business have been finishing up surveillance on UK cows due to this threat, and new legal guidelines permit them to analyze dairy cattle held near contaminated poultry. However there may be at present no routine monitoring on dairy farms or their employees.
Dr Richard Pebody, director of scientific and rising infections on the UKHSA, says there are numerous programs in place to ‘hopefully attempt to choose issues up at as early a stage as attainable’ however agreed it wasn’t attainable to ‘put plugs in every single place’.
Week two
A employee on the dairy farm develops signs of flu. It’s pretty gentle – just a few days of a excessive temperature and feeling beneath the climate – and he passes it to his spouse, a receptionist on the native GP apply.
She is distributed dwelling to recuperate, however not earlier than she has unfold the virus to a few aged sufferers, and to different members of workers. One of many nurses who picks up the virus has kids on the native major college, who themselves later develop signs which they unknowingly unfold to their classmates.
Professor Ian Brown, avian virology group lead on the Pirbright Institute, which is intently monitoring hen flu viruses as they emerge to verify whether or not they’re altering, says: ‘When persons are identified with hen flu, there’s a very speedy response system in place to establish all of their shut contacts.
‘However the issue is the lag in initiating that set off system. For those who had a sluggish burner, somebody who didn’t get notably sick however they nonetheless handed on the virus, it might unfold to a couple folks earlier than it will get to somebody who’s sick sufficient to wish hospitalisation the place they’ll be examined. As we noticed with Covid, you can get a speedy escalation of an outbreak.’
Week three
At a busy hospital in Yorkshire, 20 miles from the dairy farm, a respiratory specialist is anxious concerning the ten sufferers she has in ICU. An additional 4 kids are in paediatric intensive care.
Assessments once they had been admitted reveal all have a flu virus, nevertheless it seems to be extra extreme than the opposite seasonal flu instances she’s seen up to now this yr.
For a begin, among the sufferers are in any other case wholesome adults of their 40s who’ve developed one thing she remembers from the Covid pandemic – a ‘cytokine storm’, through which the physique’s immune system over-reacts to the virus it’s preventing, inflicting respiratory misery and injury to different organs.
‘Prior to now, highly-pathogenic strains of influenza have been uncommon in triggering this type of response in wholesome adults,’ says Professor Hutchinson. ‘We noticed it within the 1918 pandemic, and sporadically in extreme human instances of H5N1.
The primary human demise linked to H5N1 was reported earlier this month – a person in Louisiana who caught it from a yard flock
‘Within the 400-odd individuals who died of H5N1 previous to 2020, this was the kind of illness they had been experiencing.’
In the meantime, a number of nurses in ICU, and one marketing consultant in A&E the place the sufferers had been first introduced in, have come down with flu.
The respiratory marketing consultant experiences the bizarre cluster of instances to native public well being officers, who contact the UKHSA.
Week 4
Extra intensive assessments on the sufferers and healthcare employees reveal all are affected by the identical novel pressure of H5N1.
Genomic sequencing suggests the virus has mutated and is similar pressure spreading between people in components of Germany, Argentina and the US. There are whispers on social media a few unusual new bug.
Professor Sir Peter Horby, director of the Pandemic Sciences Institute on the College of Oxford and former chairman of NERVTAG, which advises the Authorities on the risk posed by new respiratory viruses, says: ‘As soon as it’s been confirmed as an avian flu virus, alarm bells would ring right away.
‘Officers will wish to see if they’ll be a part of the dots between the instances – is that this one thing spreading simply between this group of individuals or is it spreading extra extensively?
‘When you have ten extreme instances and loads of lacking hyperlinks between them, that’s the tip of a a lot greater iceberg.’
Officers hint their contacts, who will even be interviewed and examined for symptomatic or asymptomatic an infection.
They is also requested to quarantine in their very own houses and be monitored for indicators of an infection.
Any shut contacts deemed to be notably weak to flu – the aged, these with a compromised immune system or kids – may very well be given antiviral medicine to take, corresponding to oseltamivir or zanamivir. These could cut back the severity of signs and assist stop onward transmission.
The Authorities has a stockpile of those antivirals, however won’t verify how a lot it has – solely that it’s saved ‘beneath overview and knowledgeable by skilled recommendation to make sure adequate inventory is in place’.
If the outbreak is deemed to be only a cluster in a selected city, with no proof of onward unfold and shut hyperlinks between them, ‘you would possibly contemplate an area mass vaccination programme’, says Professor Horby.
The Authorities introduced final month it had ordered 5 million doses of a vaccine towards an H5 pressure from UK-based firm, CSL Seqirus UK Restricted. The corporate already produces the UK’s seasonal flu vaccines.
Dr Meera Chand, rising an infection lead on the UKHSA, mentioned the vaccine can be used ‘if this virus had been to start out spreading amongst people’.
Sadly, it’s too late to comprise the outbreak – new instances are popping up in hospitals from Plymouth to Inverness.
Week 5
The primary affected person within the UK dies of hen flu – an aged man, who’s reported to have a number of underlying well being circumstances.
NERVTAG and the Scientific Advisory Group for Emergencies, generally known as SAGE, meet and focus on how greatest for the Authorities to speak the danger.
Nonetheless, specialists say obligatory measures to regulate the virus like lockdowns and social-distancing are extremely unlikely.
Professor Sir Chris Whitty advised the Covid Inquiry the Authorities ‘overdid’ warnings in the beginning of the pandemic – so hen flu communications can be prone to contain much less doom-mongering
‘It’s unlikely folks would observe such guidelines now,’ says Professor Horby. ‘But it surely’s not Covid – it’ll be much less transmissible than Covid, as all flu strains are, and we have now vaccines and antivirals which can supply some safety and cut back transmission.’
The Authorities’s chief medical officer, Professor Sir Chris Whitty, additionally advised the Covid Inquiry that the Authorities ‘overdid’ warnings in the beginning of the pandemic – so the chances are the method would contain much less doom-mongering.
Prime Minister Sir Keir Starmer calls a press convention to announce the demise, flanked by a senior UKHSA official and Professor Whitty.
They announce that the novel hen flu virus is spreading inside communities within the UK, and that early information from modellers suggests it might result in 65,000 deaths in a ‘worst case situation’. That is twice the variety of deaths from a nasty seasonal flu yr.
In addition they level out that related predictions had been made about deaths in the course of the H1N1 swine flu pandemic in 2009, when the eventual whole was simply 457.
It proclaims that its present vaccine stockpile is being supplied to NHS workers, farm employees and essentially the most weak – the aged and people with compromised immune programs – to curb the unfold in virus hotspots.
Critics level on the market isn’t sufficient to go spherical to immunise all of the ‘weak and useful’ throughout the nation – you’d want no less than 15million doses for these teams alone.
‘Whereas 5 million doses isn’t sufficient to regulate a widespread outbreak, it might present an excellent begin by vaccinating teams uncovered within the early phases of an outbreak, notably healthcare employees and farm employees,’ says Professor Hutchinson.
The Authorities additionally says it has a ‘stockpile’ of lateral stream assessments (LFTs), nasal and throat swab assessments which might choose up flu (related variations had been used in the course of the Covid pandemic). Nonetheless, officers received’t say what number of the UK has in inventory.
These LFTs can choose up the 2 foremost varieties of flu – influenza A and influenza B – and can choose up hen flu as a result of it’s a pressure of influenza A. Such assessments are already available for purchase on-line or from excessive road pharmacies.
These testing constructive may very well be requested to remain at dwelling and to register the an infection on a (hypothetical) hen flu app – a reconfigured model of the Covid app, which might alert latest contacts that they might have been uncovered to the virus. They will even get antivirals despatched to them.
It’s unlikely the £37billion NHS Check and Hint scheme – which noticed doubtlessly contaminated Britons contacted and ordered to isolate – can be resurrected after it was discovered to be ‘muddled, overstated, and eye-wateringly costly’.
Professor Whitty recommends those that wish to put on masks ought to achieve this, and advises weak folks to keep away from crowded locations.
The Authorities proclaims it has additionally requested CSL Seqirus to offer an additional 50million doses of a brand new hen flu vaccine primarily based on the precise pressure of the circulating virus.
It has an advance contract for such an occasion – however getting it prepared and rolling it out would possibly take ‘between 4 and 6 months’, primarily based on earlier expertise, suggests Dr Pebody.
Week six
Almost 300,000 folks have seen their GP for flu-like signs previously week, which suggests the virus has formally reached ‘epidemic’ proportions within the UK.
Hospitals throughout the nation at the moment are declaring vital incidents due to ‘exceptionally excessive demand’ in A&E, and on vital care and intensive care wards.
Sadly, regardless of capability being stretched throughout Covid, with fewer ICU beds than different rich nations, this challenge has nonetheless not been addressed.
However in contrast to Covid, folks can be clearly advised that hospitals are nonetheless open for non-flu remedy – Professor Whitty advised the Covid Inquiry that the Authorities ‘didn’t get [this] throughout effectively sufficient’.
The Authorities has refused to reveal particulars of its PPE stockpile so it’s unclear whether or not the UK is in a greater place to guard healthcare employees.
‘I don’t assume mattress numbers or staffing are any higher than it was in 2020,’ says Professor Horby. ‘However what has modified is our understanding of the feasibility of home-based testing with LFTs and isolating at dwelling to maintain folks out of hospital.’
There are stockpiles of antibiotics to deal with secondary issues corresponding to pneumonia, the Authorities says.
Corticosteroids corresponding to dexamethasone, which dampens down the physique’s inflammatory response to an infection, might additionally play a job.
In the meantime, since officers confirmed the possible supply of the outbreak was a dairy farm, gross sales of beef and rooster have plummeted, with pretend information spreading on social media that folks can develop into contaminated by consuming the meats. There have been related considerations in the course of the swine flu pandemic of 2009, which induced pork gross sales to fall in some components of the world.
Public well being specialists and the Meals Requirements Company wade in to appropriate the ‘misinformation’ and reassure the inhabitants that the virus can’t unfold into people by consuming beef or rooster.
Week seven
A number of colleges are badly affected, with kids requested to study remotely in some instances due to trainer absences. Some lessons even have so many kids off with flu that the others are requested to dwelling college.
Consultants say that college closures within the occasion of H5N1 can be unlikely – despite the fact that, mockingly, flu is prone to have an effect on kids extra severely than Covid.
Dame Sally Davies, the previous chief medical officer, advised the Covid Inquiry that lockdown measures had ‘broken a era’ whereas Rishi Sunak additionally mentioned he’d argued for colleges to stay open.
In the meantime, folks have seen their cats changing into sick. Hen flu is thought to be extreme in cats – a ten-week-old kitten died in Iceland earlier this month, and 20 massive cats together with a Bengal tiger and 4 cougars have died of hen flu in a zoo in Washington state, within the US.
May this be a devastating epidemic for the nation’s felines? Typically, animals are culled to guard people – throughout Covid, Denmark culled 17million mink when a type of the virus that might unfold to people was discovered.
However specialists say the danger of catching hen flu out of your cat is ‘very low’, which suggests – on the present proof, no less than – a cat cull isn’t prone to be on the playing cards.
Week eight
How dangerous might it get? Some specialists say in a worst-case situation we might see a pandemic that rivals the Nice Influenza epidemic of 1918. That virus affected one fifth of the world inhabitants, and killed an estimated 50million folks.
However not all novel flu viruses are so harmful. In 2009, for instance, officers warned the H1N1 swine flu pandemic might trigger 65,000 deaths within the UK – in the long run, 457 folks died.
It received’t be clear how severe a hen flu pandemic may very well be till it arrives. What issues is the case fatality fee – how many individuals die after being contaminated – and the way simply it spreads.
MERS, a kind of coronavirus that appeared within the Center East in 2012, kills 35 per cent of these contaminated – round one in three. But it surely doesn’t cross simply between folks, so has in the end led to fewer than 1,000 deaths.
Covid, in the meantime, had a a lot decrease case fatality fee. The unique Alpha pressure killed 2.62 per cent of these it contaminated. Nonetheless, as a result of it might unfold swiftly it contaminated greater than 700million folks, killing seven million.
Normally, flu doesn’t unfold as simply as Covid. However as epidemiologist Professor Mark Woolhouse from the College of Edinburgh explains: ‘The worst-case situation is we get a pressure that mixes the virulence of among the hen flus with the transmissibility of among the human flus. That has been the priority for 30 years.
‘If it’s a really seen, extreme an infection then it must be simpler to comprise if we throw all of the contact tracing functionality we have now at it.
‘If it strikes quick and fewer visibly throughout the inhabitants, containing will probably be tougher so we might even see extra deaths and severe sickness total, even when the signs are milder for most individuals.’
And what would possibly occur subsequent?
As time goes on, and the 50million vaccine doses are rolled out, immunity within the inhabitants builds up.
Like throughout Covid, there are a number of totally different waves of an infection. The virus will even evolve, as Covid did.
However ultimately, H5N1 might develop into like another seasonal flu. ‘It’s going to stick with us, like Covid did,’ says Professor Woolhouse.
