Senior GPs said yesterday they are "deeply concerned" that a major flu crisis is brewing.
Fewer patients in at-risk groups – including pregnant women and those with diabetes and heart disease – are coming forward for the seasonal flu jab.
The vaccine protects against swine flu, which is circulating again this winter, as well as other types, including flu type B.
Even those people in at-risk groups who had the swine flu jab last year should come forward for the new seasonal vaccine, according to the Department of Health.
Yesterday, the British Medical Association (BMA) said lower immunisation rates have increased fears that a normal seasonal flu outbreak could prove much more serious this time.
An estimated 67.2 per cent of over-65s and 41.5 per cent of under-65s in at-risk groups have had the flu jab in England.
This is just behind last year's figure for the over-65s, but five per cent behind vaccination rates seen this time last year for at-risk groups.
Chairman of the BMA's GPs committee Dr Laurence Buckman has written to the Government urging it to step up its publicity campaign.
He said: "Family doctors are already seeing high rates of influenza and they have been telling us that they are also seeing a lower uptake than usual for seasonal flu immunisation.
"Myths persist about the safety of the vaccine, especially after swine flu.
"The vaccine has been thoroughly tested and we strongly urge patients to make an appointment with their GP and get vaccinated."
Figures out yesterday revealed 17 people have died from flu so far this winter. The Health Protection Agency (HPA) said 14 deaths were from swine flu and another three from flu type B.
Of those who died, all were aged under 65, with six deaths among children under 18. At least eight of the 17 people was in an "at-risk" group. None was pregnant and none had been vaccinated.