The HSE is warning that a number of people have already died as swine flu returns to Ireland.

The health service said over 200 people have been diagnosed with the strain – known as H1N1 – over the past six to eight weeks.

It has hit Ireland a number of times since the Swine Flu Pandemic a decade ago – however, the flu vaccine has been updated and the public as a whole has grown more accustomed to it.

Dr Kevin Kelleher, assistant national director of public health at the HSE, said the best way to protect against all forms of flu is to get the vaccine.

“We are now fairly certain that the flu season is about to begin,” he said.

“We are asking people to be aware of that and to get the vaccine – particularly those people who are under 65 with medical conditions such as asthma or diabetes or things of that nature.

“Or if they are pregnant women they should equally get the vaccine as well.

He said children and the elderly are most at risk from the H1N1 strain - which is dominant this season.

“But it then has this particular predilection to cause severe respiratory disease in a number of people who are under 65 with pre-existing disease and pregnant women.

“Then unfortunately it will just do it randomly in totally well people as well.

“So it has a particular issue about causing very serious disease and those people will end up in ICU and unfortunately a number will die.”

He said every year between 30 and 100 people die directly from the flu – with between 300 and 500 dying indirectly from the disease.

“A flu season normally lasts somewhere between six and ten weeks so, on average, three of four people will die each week directly from the flu,” he said.

He said this year’s flu vaccine is a good match for all strains of the disease in Ireland and people in at-risk groups – young children, the elderly, pregnant women and people with chronic illness – should get it as soon as possible.

Healthcare workers should also get vaccinated to protect themselves and those that they care for.

“While most people will get better themselves from flu, anyone who is concerned about their condition should telephone their GP or an out of hours medical service so they can arrange to be treated in a way that does not put others at risk,” said Dr Kelleher.

“People with symptoms should stay at home and children should not attend school if showing signs of flu.”