Health chiefs at NHS Bradford and Airedale are being supported by Bradford Chamber of Commerce in a bid to promote the importance of having the swine flu jab to at-risk employees.

About a fifth of the local population falls within at risk groups and GPs are currently contacting patients who are eligible for vaccinations against both seasonal flu and swine flu.

Dr Peter Dickson, medical director of Bradford and Airedale, said: "Winter could be a challenging time and it is anticipated that staff absence could be a significant issue for many organisations.

"Getting 'at-risk' employees vaccinated will not only help everyone stay healthy, but also help keep teams at work and ahead of the game.

"Swine flu is different to seasonal flu, to which many people have an in-built resistance.

"As a new virus, very few of us have any resistance to swine flu – meaning that if you never seem to catch normal flu, you won't necessarily be immune to swine flu," he said.

"This vaccine has been well-tested, is safe and the balance of risks for someone considering swine flu immunisation is strongly in favour of having the vaccine."

Among those being invited to have the swine flu vaccine are: pregnant women; people aged between six months and up to 65 years that have ongoing health conditions such as asthma and chronic heart disease;people whose immune systems are not working properly due to disease or treatment such as cancer treatment; people with HIV and people who have had treatments with steroids for prolonged lengths of time.

Employers are also being encouraged to reduce the risk of their workforces getting swine flu by promoting good hygiene practices such as ensuring that cleaning staff was hard surfaces very frequently.

Doctors are also advising people not to go to work if they begin to feel ill and to send them home if they show symptoms while at work. Such individuals should stay off work until they are no longer infectious – usually about five days after symptoms appear.