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Flu vaccine overview

The flu is a contagious viral infection that spreads every winter. Getting the flu vaccine is the best way to protect yourself against flu.

The best time to get the flu vaccine is before the flu season starts.

It is available from October to the end of April each year.

Who can get a free flu vaccine

Older people and flu vaccine

People age 65 and older who get flu are at higher risk of serious illness.

Flu vaccine for people age 65 and older

Pregnancy and flu vaccine

The flu vaccine can prevent you from getting flu and passing it on to your baby.

The flu vaccine is safe in pregnancy.

Getting the flu vaccine while pregnant

Children and flu vaccine

All children age between 2 and 17 can get the nasal flu vaccine.

Flu vaccine for children

Healthcare workers and flu vaccine

We recommend that healthcare workers get their flu vaccine to help protect themselves, their patients and the people they work with.

Read more about flu vaccine for healthcare workers

Flu vaccine and egg allergy

If you have an egg allergy, talk to your vaccinator before getting the vaccine. Most people with an egg allergy can get the flu vaccine.

How the flu vaccine works

The flu vaccine helps your immune system produce antibodies to fight infection. Having the vaccine can stop you from getting sick if you come in contact with the flu virus.

Getting the flu vaccine is the best way to protect yourself against flu. The vaccine starts to work after about 2 weeks.

Protection from the flu

Most people who get the vaccine will be protected from the flu. You can still get the flu after vaccination. But you should have milder symptoms and recover faster.

We do not know yet how effective this year's vaccines are. But normally the vaccine reduces the risk of getting flu by 40% to 60%. You need to have the flu vaccine every year. This is because the antibodies that protect you fade over time. Flu strains also change each year.

Who should not get the flu vaccine

You should not get the flu vaccine if you:

  • had a severe allergic reaction to a previous flu vaccine or any part of the vaccine (including polysorbate-80)
  • are taking medicines called combination checkpoint inhibitors, for example, ipilimumab and nivolumab
  • have a temperature of 38 degrees Celsius or higher - wait until you are well before getting the vaccine
  • have severe neutropoenia - low levels of a type of white blood cell

If you have primary autoimmune neutropenia, you should be able to get the flu vaccine. Talk to your GP if you are not sure.

Flu vaccine and other vaccines

It is safe to get the flu vaccine even if you had other vaccines recently.

For example, if you have had your:

Children aged 6 months to 4 years should wait 14 days after getting a COVID-19 vaccine before getting a flu vaccine.

Children age 12 to 23 months who are medically at-risk

Wait at least 1 week between the flu vaccine and the pneumococcal vaccine. This reduces the risk of fever-related complications.

Protect yourself from flu

If you do not get the flu vaccine, you need to take extra care to protect yourself.

Protect yourself from flu by:

  • washing your hands properly and often with soap and water or alcohol hand sanitiser
  • covering your mouth and nose with a tissue or your sleeve when you cough or sneeze
  • putting used tissues into a bin

All HSE immunisation programmes follow the recommendation of the National Immunisation Advisory Committee (NIAC).

Page last reviewed: 30 November 2023
Next review due: 6 September 2026