- Flu is a respiratory illness linked to infection by the influenza virus.
- Symptoms usually include headache, fever, cough, sore throat, aching muscles and joints.
- Influenza occurs most often in winter and usually peaks between December and March.
- The virus was first identified in 1933.
- There are two main types that cause infection: influenza A and influenza B
- New strains of the virus are constantly emerging, which is why the flu vaccine should be given each year.
Previously, only children in “at risk” groups were offered the protection.
Scotland’s largest ever immunisation programme was launched by First Minister Alex Salmond, who received the vaccine in a surgery in Aberdeenshire.
He said that as an asthmatic, he gets the injection every year and urged other eligible Scots to get protected before the winter.
A fifth of the Scottish population will be offered a free flu vaccine, including people aged over 65 and those with conditions that put them at greater risk.
For the first time, all two and three-year-olds – about 120,000 children – will be offered the vaccine, as well as 100,000 primary school pupils in health board areas which are taking part in a pilot programme.
The programme will be rolled out to eventually see about one million children aged between two and 17 have the chance to be immunised towards the end of 2015.
The vaccine will take the form of a nasal spray rather than an injection.
Scotland’s senior medical officer said the spray, which is being phased in this autumn and rolled out over the next two years, was more effective in children than injections, as well as simpler to administer.
Speaking after receiving his own vaccine, Mr Salmond said it was better to be safe than sorry.
“As an asthmatic, I get my flu vaccination every year to make sure I’m protected and ready for the winter and I’m delighted to launch this national campaign,” he said.
“It is hugely successful and the existing programme has seen 2,000 fewer hospitalisations and 25,000 fewer GP consultations.
“For the first time this winter we are taking extra precautions to protect families by making sure children are also offered this vital vaccine.”
Senior medical officer Dr Nicola Steedman said every year she sees examples of how devastating flu can be.
She added: “For those with existing health conditions such as asthma, diabetes, heart or liver problems, flu can result in serious complications.
“Furthermore, those who are pregnant or over 65 are also at increased risk of flu and its complications and should be vaccinated to help protect against flu, even if they currently feel healthy and fit.
“Flu can also be very serious for children, particularly the youngest ones who have little or no immunity to the infection, which is why we are rolling out the new childhood flu immunisation programme.”
All two and three-year-olds in England and Wales will be also offered the vaccine this winter. In Wales, children aged 11 to 12 will also be eligible, while children aged between two and 10 in certain areas of England will be offered protection.