The annual UK campaign to urge people to take advantage of an offer of a free flu jab has been launched with the help of former boxer Sir Henry Cooper.

GP practices across Sussex will be spending the next couple of months vaccinating thousands of people as part of a drive to keep the county's elderly and vulnerable people healthy.

Many surgeries are holding special flu jab sessions and are contacting patients asking them to come in.

The campaign was launched in 2000 following the mass flu epidemic which swept across the county in 1999. Hospitals were filled to bursting point and many people died.

Free vaccination against flu is being offered to everyone aged 65 and over and those, whatever their age, with a chronic heart or chest complaint, including asthma, chronic kidney disease or diabetes.

People with lowered immunity due to disease or treatment such as steroid medication or cancer treatment are also eligible.

Elderly people in residents and nursing homes are also being targeted.

Dr Angela Iversen, a consultant in communicable disease control working at Brighton and Hove City Primary Care Trust, said:

"For most people, flu is an unpleasant experience but it can be a very serious illness for older people or those in the at risk' groups.

"If you have not already done so, you should contact your surgery to find out what their flu vaccination arrangements are. You should not wait until there is a flu outbreak.

"Flu vaccination is safe and effective. Most people experience no, or only very minor, side effects and the vaccine cannot give you flu."

For some people, flu can lead to more serious complications such as bronchitis and pneumonia which may need treatment in hospital.

When the campaign first launched there were teething problems with supplies and many patients experienced problems getting their vaccinations.

The campaign is now in its third year and GPs are better prepared and able to more accurately assess what the demand will be.

Primary Care Trusts are working closely with GPs in areas where there is a low take-up of the vaccine to try and find ways to improve vaccine rates.

These include mass mailshots, phoning patients directly and holding drop-in clinics.

Health bosses say vaccinations can usually offer about 70 per cent protection against flu but there can never be a perfect solution.

Some people eligible to receive the vaccine are not happy about having it.

They are urged to get in contact with their GP or call NHS Direct to discuss their case so they can make a fully-informed choice.

It can sometimes be difficult to distinguish between flu and a very heavy cold.

Flu tends to start suddenly with symptoms such as fever, chills, headache, aching muscles and feeling generally unwell, together with a cough or sore throat.

Colds are more likely to start gradually, with a sore throat, stuffy and runny nose and are less severe.

Flu is spread by the coughs and sneezes of people who are already infected with the virus and can spread very rapidly.

The campaign is expanding every year with new ideas coming forward each time.

Today, shoppers at the two Asda stores in Brighton will be offered the vaccination.

Two nurses will be on hand to give customers advice and information and people will be asked to complete a questionnaire before the vaccination is given.

The jab will cost just less than £12.

All of the company's stores will be taking part in this one-day campaign which, if successful, may be expanded to other shops next year.

Anyone who is unsure if they should have a flu jab should check with their GP's surgery or NHS Direct on 0845 4647.