In the third part o fhis investigation into the North-East's feadiness for a flu pandemic, Health Editor Barry nelson considers how we can limit the effects of the potentially deadly illness.

EXPERTS are predicting that the North-East can expect to be engulfed by the most serious outbreak of flu since the late 1960s any day now. It might not be this year, it might not be next year, but specialists who study flu viruses say a potentially devastating 'pandemic' flu outbreak is long overdue and can be expected at any time.

Unlike the normal winter flu, the expected pandemic could strike during the spring or summer and virtually no-one will have any immunity. The Government anticipates that the pandemic outbreak could claim 50,000 British lives - however a 'worst case' prediction suggests that up to 750,000 people could die in the UK alone. While we are expected to get quite a bit of notice - experts believe the pandemic will begin in South-East Asia and take weeks to travel to the UK - the treatment options are very limited.

Unlike vaccines for normal winter flu, the medical authorities do not have a ready-made stock of those for pandemic flu which can be distributed throughout the population to protect people. This is because experts will not know precisely what strain of flu is responsible for the worldwide outbreak until it happens. It means a time lag of between four and six months - if not longer - before supplies of an appropriate vaccine reach the UK.

Until the vaccine arrives - and there is no guarantee there will be enough for everyone because of capacity problems in the vaccine industry - the only measures the authorities can take are to try to control outbreaks with the anti-viral drug Tamiflu and advise the rest of the population to follow guidelines designed to reduce the risk of infection. According to the UK Influenza Pandemic Contingency Plan, in the event of an outbreak, everyone will be advised to take these precautions:

l Wash your hands (especially after you have been outside) to prevent acquiring the virus from contact with infected people or contaminated surfaces.

l Cover your mouth when coughing or sneezing to limit the spread of the virus.

l After blowing your nose, make sure you put used tissues in the rubbish bin.

l Avoid crowds and large gatherings where possible.

As part of efforts to reduce the spread of the pandemic flu virus, the Government could advise people to avoid travel, close schools and cancel events where large crowds gather, such as football matches or pop concerts.

Dr Nonnie Crawford, director of public health for Darlington Primary Care Trust, says most people who become ill will be advised to stay at home, go to bed, take paracetamol tablets or other over-the-counter painkillers to cope with symptoms and wait until the illness passes. In the great majority of cases, this should be within a fortnight, with patients having to stay in bed for a week and then recovering for a further week.

But Dr Crawford acknowledges that in the event of a pandemic, some patients could become seriously ill with secondary conditions such as pneumonia. It is these patients who will be given priority by the NHS, which will increasingly rely on telephone advice from NHS Direct and telephone consultations because of the risk of spreading disease.

Worried members of the public who have access to computers will be urged to visit the www.nhsdirect.nhs.uk website for advice and information.

As part of efforts to reduce the spread of the virus, doctors' surgeries and walk-in health treatment centres could be closed temporarily until the crisis passes. People with flu symptoms would also be asked not to go to accident and emergency departments at their local hospitals. Dr Crawford says patients needing repeat prescriptions might need to pick them up at a pharmacy rather than go to their doctor, and that preventative measures need to be put in place to prevent pregnant women arriving at maternity units and coming into contact with patients with flu symptoms. However, patients who became seriously ill would be monitored by telephone and assessed by mobile groups of doctors and specialist nurses and transferred to local hospitals if their condition deteriorated. By then, most hospitals would probably have cancelled routine work to tackle the expected flood of emergency flu victims.

Recently, the Health Protection Agency revealed that a limited supply of Tamiflu, a proven anti-viral drug which can reduce the severity of symptoms and limit the chance of pandemic flu spreading to others, was now available in the North-East. The Government has ordered more than 14m doses of Tamiflu from the pharmaceutical company Roche. However, because Roche's factories in Switzerland can only make so many doses in a year, the order is not expected to be fulfilled until September 2007.

In its contingency plan, the Department of Health admits that there will not be an "unlimited supply" of anti-viral drugs such as Tamiflu. While they may initially be used to try to contain small outbreaks of flu, more widespread use will be restricted according to guidelines drawn up by the Government. These guidelines will identify priority groups, which could include people with chronic underlying health problems and front-line health workers.

A spokeswoman for Roche says: "Tamiflu is licensed in the UK for the treatment of flu and the prevention of infection. If you take two 75mg capsules every day for five days, within two days of developing symptoms, it can reduce the severity and duration of the illness. Importantly, it can also reduce the risk of hospitalisation."

The spokeswoman explains that Tamiflu is a new class of anti-viral drug which works by interfering with the way the flu virus reproduces itself.

"It is designed to act on all human strains of the flu virus. We anticipate it will be effective against human pandemic flu."

The authorities in Turkey are using Tamiflu to try to stamp out a virulent strain of bird flu known to scientists as H5N1, which has caused international alarm by spreading from infected birds to humans. Fortunately, there is still no sign that the virus has mutated to allow it to spread from human to human. The World Health Organisation (WHO), which is monitoring the situation, believes H5N1 could evolve into pandemic flu in humans but experts say there is just as much chance of 'normal' flu viruses mutating into a more aggressive form of flu which could trigger a pandemic outbreak.

Alison Lawrence, who speaks for the UK Vaccination Industry Group (UVIG), says that once the WHO has identified the precise strain of flu which is causing the pandemic, a quantity of virus - known as a "seed" - is passed to the vaccine makers. Bizarrely, the medium used to grow the flu virus is fertilised chicken eggs.

Once it is cultured, the virus is harvested, mixed with a preservative and then placed into syringes ready to be used.

The Government has placed an advanced order, or 'tender' for 120m doses of vaccine with UVIG but the lack of capacity in the industry makes it unlikely that the vaccine makers will be able to fulfil the order. That is why the industry has asked the UK Government - along with other European governments - to increase its demand for 'normal' winter flu vaccines every year.

The aim is to allow the industry to build the additional factories which will be needed to produce enough vaccine does for the 450m people who live in the European Union.

"We need to sit down and work out the best way of moving forward. We are very interested in what can be done in normal flu years to help build up that capacity," says Ms Lawrence.

Worryingly, if the pandemic was declared tomorrow, UVIG believes the maximum number of vaccine doses which could be produced is around 36 million, which, on the basis of two doses per patient, would only serve around a quarter of the UK population.

A breakthrough announced yesterday may be a way out of this conundrum.

US researchers have genetically engineered a vaccine which can protect mice from different human strains of the H5N1 flu virus. They believe this new way of making vaccine could meet the worldwide demand for pandemic flu vaccine.

Whatever happens in the months and years to come, the people of the North-East must prepare themselves for what is expected to be the greatest health emergency for nearly 40 years