Influenza (flu) is a highly-infectious, acute, respiratory illness caused by the flu virus. Flu affects people of all ages, with outbreaks occurring almost every year.

Flu symptoms come on suddenly with a fever, muscle aches, headache and fatigue. This is different from a cold, which is a much less-severe illness compared to flu.

A cold usually starts gradually with a sore throat and a blocked or runny nose. Symptoms of a cold are generally mild compared to flu.

In some instances, flu can be severe and can cause serious illness and death. Serious breathing complications can also develop. This includes pneumonia and bronchitis, to which older people and those with certain chronic medical conditions are particularly susceptible.

Some people may need hospital treatment and a number of people die from flu each winter. Each year, the seasonal (annual) flu vaccine contains three common flu virus strains. The flu virus changes each year and this is why a new flu vaccine has to be given each year.

The best way to prevent flu is to get the flu vaccine.

The vaccine is recommended for:
  • All those 65 years-of-age and over;
  • Those with long-term medical conditions such as heart or lung disease;
  • All front-line heatlhcare workers, including carers.

Vaccination should ideally be undertaken in September or October each year. Flu vaccines have been used for more than 60 years worldwide and are very safe.

Flu vaccine contains killed or inactivated viruses and, therefore, cannot cause flu. However, it does take 10-14 days for the vaccine to start protecting you against the flu.

The vaccine and consultation are free to those within the recommended groups who have a ‘Medical Card’ or ‘GP Visit Card’.

GPs (general practitioners) charge a consultation fee for seasonal flu vaccine to those who do not have a ‘Medical Card’ or ‘GP Visit Card’. More information is available from your GP, public health nurse or pharmacist. provides details about flu vaccination, along with answers to any questions you may have about flu.

Pneumococcal vaccine

If you are over 65 or have a long-term medical condition, you should also ask your doctor about the pneumococcal vaccine – which protects against pneumonia – if you have not previously received it. You can get the flu vaccine at the same time as your pneumococcal vaccine. Click here for more information