Pregnant women at highest risk during flu season
Flu took the hardest toll on older people last winter with the over-65s accounting for 26 official deaths from the illness.
Figures show 34 recorded flu-related deaths - although the real number is much higher and runs into hundreds.
There were 34 deaths in all; one in a 0-4-year-old, one in a 5-14-year-old, six in 15-64-year-olds and 26 deaths were in patients aged 65 years and over. The median age of cases who have died was 80 years.
Hospitals reported 670 confirmed cases of patients admitted with flu with the highest rates among infants and the over 65s.
Of these, 82 had to be admitted to intensive care and 57 were children under 15 years.
Complications of flu mostly affect high-risk groups, such as the elderly, pregnant women and those who have a long-term medical condition or weakened immune system.
Although the flu season is thankfully some time away, stocks of vaccines are already beginning to be piled up, ready for autumn.
Flu viruses are constantly changing and it is not unusual for a new form to appear each year. It is not possible to predict with certainty if the vaccine that is available will be a perfect match for circulating viruses.
The vaccine is made to protect against the flu viruses that research indicates will likely be most common during next winter. Flu viruses also change constantly even within the course of one flu season.
It is only over the course of the winter that laboratory samples sent to the national virus laboratory in Dublin show how good a match the vaccine is against the circulating strains.
The vaccine also does not provide full protection against the flu. Older people and those whose immune systems are weakened may not have the same reponse to the jab as the healthier population.
Vaccination is particularly important for people at high risk for serious flu complications, and their close contacts.
Antibodies made in response to vaccination with one flu virus can sometimes provide protection against different but related viruses.
A less than ideal match may result in reduced vaccine effectiveness against the virus that is different from what is in the vaccine, but it can still provide some protection.
In addition, the flu vaccine contains three or four flu viruses (depending on the type of vaccine you receive) so that even when there is a less than ideal match or lower effectiveness against one virus, the vaccine may protect against the other viruses. There is good evidence that pregnant women have a higher chance of developing complications if they get flu, particularly in the later stages of pregnancy.
One of the most common complications is bronchitis, a potentially serious chest infection.
Health & Living