People who are at a higher risk of contracting the flu virus should visit their GP and receive the vaccine, health chiefs have urged.
The appeal comes after it was revealed that 10 adults in the UK have died from swine flu in the last six weeks. The deaths were associated with H1N1 swine flu, which swept the country last year, and were in younger adults under 65, the Health Protection Agency (HPA) confirmed.
A spokeswoman said that while most already had underlying conditions, "a small proportion" were in good health before being struck down with the virus.
The deaths come at a time when the number of GP visits relating to flu is at a low rate. Consultations about flu-like symptoms in England last week were 13.3 per 100,000 population.
Professor John Watson, head of respiratory diseases department at the HPA, said: "Over the last few weeks we have seen a rise in the number of cases of seasonal flu, including both H1N1 (2009) and flu B, in the community. We have also received reports of patients with serious illness requiring hospitalisation and outbreaks of flu in schools across the country.
"For most people, flu is not life threatening and usually lasts seven to 10 days. However, it can be far more dangerous for those in at-risk groups, such as the elderly, pregnant women and patients with heart problems, diabetes or lung, liver or renal diseases, or those who have weak immune systems who are at risk of developing complications."