Brace yourselves: the worst flu epidemic for 50 years is on the way to the UK.
In September, it was reported there had been 170,000 influenza cases in Australia, twice that of 2016, and more than 70 flu-related deaths, which affected those over the age of 80 and children aged 5-9 the most.
Experts warn that it is "inevitable" that the dreaded 'Aussie flu' will make its way to these shores - so now is the time to start thinking about flu jabs.
Professor Robert Dingwall, a public health expert at Nottingham Trent University said the outbreak presents the most serious challenge since the 1968 flu pandemic which originated in Hong Kong and killed a million people worldwide.
Prof Dingwall said: “Based on the Australian experience public health officials need to meet and urgently review emergency planning procedures. We need to be prepared, alert and flexible.
“There is no point in trying to close the borders. It’s almost inevitable this will come to us. This is potentially the worst winter since the Hong Kong flu outbreak of 1968. Lots of people have been very badly affected in Australia and whilst their mortality rates are not out yet we suspect this is a more severe strain than most other years.”
'Aussie flu' or otherwise, the flu is a largely unpredictable virus which affects people in different ways.
For the majority of people, it can cause symptoms that last for around a week, but there are some vulnerable group - the elderly, pregnant women, asthma sufferers - who are at a far higher risk, with potentially serious complications.
Indeed, according to The Vaccine Knowledge Project - an academic research group in the Department of Pediatrics at the University of Oxford - in the UK an average of 600 people a year die from complications of flu, but in some years this can rise to over 10,000 people.
Flu leads to hundreds of thousands of GP visits and tens of thousands of hospital stays a year.
The flu virus is very variable and changes over time. Each year there are different strains around, and a new vaccine has to be prepared to deal with them. Vaccination from previous years is not likely to protect people against current strains of flu.
There are three basic types of flu: A, B and C.
Type A is the most dangerous; it is the one that can cause serious disease and also triggers worldwide pandemics.
Type B can make you feel very ill, but it has never led to a worldwide pandemic.
Type C causes mild disease.
Flu can kill thousands or even millions of people. The 1918 flu pandemic is estimated to have affected half the world's population, and killed 40-50 million people worldwide.
Everything you need to know
When is flu season?
In a nutshell, right now. In the UK the annual flu season runs from about October to March or April. The majority of cases of flu occur between December and February.
What are flu symptoms?
Unlike the common cold, which comes on gradually, flu symptoms often hit fast with sufferers experiencing a fever, a dry chesty cough, tiredness, the chills, joint pain or aching muscles. Most of the time it will make them too unwell to do anything.
Other symptoms include: diarrhoea, abdominal pain, nausea, vomiting, sore throat, blocked or runny nose, sneezing, loss of appetite and difficulty sleeping.
How the flu jab works
The injected flu vaccine stimulates your body's immune system to make antibodies to attack the flu virus.
Antibodies are proteins that recognise and fight off germs, such as viruses, that have invaded your blood.
If you're exposed to the flu virus after you've had the flu vaccine, your immune system will recognise the virus and immediately produce antibodies to fight it.
It may take 10 to 14 days for your immunity to build up fully after you have had the flu shot.
You need to have a flu jab every year, as the antibodies that protect you from flu decline over time, and flu strains can also change from year to year.
How the annual flu jab changes
In February each year, the World Health Organization (WHO) assesses the strains of flu virus that are most likely to be circulating in the northern hemisphere over the following winter.
Based on this assessment, WHO recommends which flu strains the vaccines should contain for the forthcoming winter. Vaccine manufacturers then produce flu vaccines based on WHO's recommendations. These flu jabs are used in all the countries in the northern hemisphere, not just the UK.
Production of the vaccine starts in March each year after WHO's announcement. The vaccine is usually available in the UK from September.
Who should get the flu jab?
Between 2017 and 2018, the flu vaccination is recommended for and offered free of charge to:
The over 65s
Those aged six months to under 65 in clinical risk groups
People residing in a residential or nursing home
Those who care for an older or disabled person
Children aged 2-3
Children at nursery or at school in primary 1-4 (with parental consent)
Everyone should get the flu jab, though. If you still get the flu, the vaccine helps you fight off life-threatening complications.
Where can you get the flu jab?
To get your vaccine or find out if you are eligible, contact your GP, pharmacist or midwife. Some employees are offered the flu vaccine through their work’s health scheme.
You can also pay for the flu jab at a range of pharmacies including Boots, Superdrug and Lloyds Pharmacy, as well as in the likes of Sainsbury’s, Tesco and Asda.
Asda is offering the flu jab for just £5, making it the cheapest option outside the NHS. At Boots, the flu jab will set you back £12.99, which is still cheaper than all the medicines you'll need if you catch flu.
When should you get the flu jab?
The NHS says the best time to get the flu jab is in autumn, between early October and November. So right now. You can also be vaccinated later in winter if you miss this window.
What are flu jab side effects?
Contrary to what you may have heard, you can’t catch the flu from the flu jab. The adult vaccine doesn’t contain live viruses.
Granted, you may feel a mild fever or muscle aches after your jab, but this is your immune system reacting to the vaccine. These symptoms should pass after a day or two.