Swine flu has killed 14 people in the UK this winter, according to the Health Protection Agency.
The agency confirmed that 17 people in total had died from influenza since the start of the winter flu season, which began in early October.
Swine flu was responsible for all but three of these deaths, which were caused by flu type B, a spokeswoman said.
She said both of these strains were included in the current flu vaccination programme, and urged eligible groups to ensure they have had the jab.
Professor Dame Sally Davies, interim chief medical officer for England, told the BBC’s The World At One that flu was not more prevalent than for the same period in previous years.
But she added: “We’ve had a rise in reports over the past week - 35 cases per 100,000 (people) consulting their GPs, from 13 the previous week.
“What we are looking at is three viruses, and we are seeing all of those three viruses.
“The issue I’m very concerned about is we’re not getting everyone at risk - including pregnant women - vaccinated.
“Our vaccine uptake is about 2% down on last year so we’re doing better than many other countries, but when young people come in - particularly with H1N1 (swine flu) to hospital - most of them don’t seem to have been vaccinated.
“They could prevent serious illness and death and it’s very important that they get vaccinated.”
She said most people in this country were sensible and knew how to look after themselves, most of them staying at home.
“What I’m asking people to do is if they are in risk groups or pregnant, to go and get vaccinated so they protect themselves and they don’t pass it on to others.”
The NHS had capacity for dealing with flu and could increase that if needed, she added.