People in at-risk groups are being urged to get their flu jabs before the onset of winter.
GPs are in the process of inviting eligible patients – including pregnant women, over-65s and those with long-term health conditions – to have a vaccination.
"If you receive a letter from your GP – or employer – it’s because you need to protect yourself from the flu," said Ralph Saunders, Bradford Council's head of public health.
"Flu is very contagious and can be a really serious illness.
"Having the vaccine doesn’t just protect you; it helps stop the flu spreading to other people who may be even more vulnerable than yourself."
As part of this year's programme, children aged two to four are also being offered the vaccination, through a nasal spray.
Anyone who believes they are eligible but has not received a letter should contact their GP.
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