A total of 27 people have died from influenza this winter, including nine children, latest official figures show.
Of those who died, 24 had swine flu and three were suffering from another strain, influenza type B.
The data, from the Health Protection Agency (HPA), relates to the number of confirmed flu deaths across the UK since October.
Almost half of those who died were in an “at risk” group, such as those suffering from diabetes, heart disease or asthma. The HPA would not confirm if any of the deaths were among pregnant women because of worries over identification.
Just one of the people who died - and whose vaccination status was known - had received this year’s flu vaccine.
A spokeswoman for the HPA said the flu jab was only 70 per cent to 80 per cent effective, meaning somebody could still potentially die from flu if they were vaccinated but had an underlying serious illness.
“It is not a vaccine failure; it means the person’s illness is so serious that they are very weak,” she said.
Separate figures, published yesterday by the Royal College of GPs, showed rates of flu infection have more than doubled in the last week.
Cases of flu have risen to 87.1 per 100,000 of the population in England and Wales, from 32.8 in the previous week.
Rates of flu are highest in children aged five to 14, followed by those under four, then people aged 15 to 44.
Professor Dame Sally Davies, interim chief medical officer for England, said rates of flu were within the expected range for the time of year.
“Clearly, any death is sad for the family and the patient and we don’t like it,” she told the BBC. “But 27 deaths at this stage of seasonal flu is not a large number.”
A Department of Health spokesman said: “Our influenza immunisation programme has been designed to protect those particularly at risk from serious disease, either from influenza itself or in whom influenza would make their underlying disease worse.
“This means that we use an age and risk group based approach in line with most other countries that have seasonal influenza vaccination programmes.”
He added: “We continue to monitor the current situation very carefully and the Joint Committee on Vaccination and Immunisation keeps the policy for seasonal influenza vaccination under review as well.”