Flu vaccine

The seasonal flu vaccine (flu jab) protects against 4 strains of flu virus. These are the strains most likely to be circulating this flu season.

The vaccine is available every year to adults and children at risk of flu and its complications.

You need to get a new vaccine every Autumn. This is because the strains of the flu virus change. This is why it is called seasonal flu. But people commonly call it flu.

You should get your flu vaccine during the Autumn, to be covered for flu season.

Flu vaccine is recommended

Some people are more at risk of getting complications if they catch flu.

You can get the flu vaccine for free if you:

  • are 65 years of age and over
  • are pregnant
  • are a child aged 2 to 17 years 
  • are an adult or child aged 6 months or older at increased risk for flu related complications including
    • those with long term conditions
      • chronic heart disease, including acute coronary syndrome
      • chronic liver disease
      • chronic renal failure
      • chronic respiratory disease, including chronic obstructive pulmonary disease (COPD), cystic fibrosis, moderate or severe asthma or bronchopulmonary dysplasia
      • chronic neurological disease including multiple sclerosis, hereditary and degenerative disorders of the central nervous system
      • diabetes mellitus
      • haemoglobinopathies
    • morbid obesity i.e. body mass index (BMI) over 40
    • immunosuppression due to disease or treatment (including treatment for cancer)
    • children with a moderate to severe neurodevelopmental disorder such as cerebral palsy
    • children on long term aspirin therapy 
    • those with any condition that can compromise respiratory function (e.g. spinal cord injury, seizure disorder or other neuromuscular disorder) especially those attending special schools or day centres
    • were born with Down syndrome
  • live in a nursing home or other long-term care facility
  • some people should get the vaccine to protect themselves, their families and those they care for. These include
    • those who work in healthcare
    • only household contacts or carers of people who have an underlying chronic health condition or have Down syndrome are eligible to receive an influenza vaccine. A carer is described as someone who is providing an ongoing significant level of care to a person who is in need of care in the home due to illness or disability or frailty.
  • People who are in regular contact with pigs, poultry or waterfowl should get the flu vaccine. 

Please note: household contacts of people aged 65 years and older (who do not also have a chronic health condition), pregnant women, children aged 2-17 years or of healthcare workers or carers are NOT recommended the influenza vaccine.

If you are in an at-risk group, you should get the flu vaccine during Autumn.

Where to get the flu vaccine

You can get the flu vaccine from:

  • your GP 
  • a local pharmacy
  • an occupational health department or peer vaccinator if you work in healthcare

How the flu vaccine works

The flu vaccine helps your immune system to produce antibodies (proteins that fight infection). If you have had the flu vaccine and you come into contact with the flu virus, the vaccine can stop you from getting sick

The flu vaccine starts to work within 2 weeks.

You need to have the flu vaccine every year. This is because the antibodies that protect you decline over time. Flu strains can also change from year to year.

Flu vaccine and COVID-19 (coronavirus)

The flu vaccine doesn’t protect against COVID-19. It is important to get both the flu vaccine and the COVID-19 vaccine. This is because Flu and COVID-19 are caused by different viruses.

If you have had the COVID-19 vaccine you should still get the flu vaccine.

Safe and effective flu vaccine

Getting the flu vaccine is the best way to help protect yourself from getting the flu.

It will not stop all flu viruses and the level of protection may vary. So it's not a 100% effective and you may still get flu.

But if you do get flu after you have the vaccine, it's likely to be milder and you will recover more quickly.

Flu vaccines usually reduce the risk of infection by 40-60%.

Flu vaccines also reduce:

  • the severity of illness
  • complications from influenza
  • flu-related hospitalisations
  • admissions to critical care units

Flu vaccines have been given to millions of people worldwide for over 60 years, including pregnant women. Reactions to the vaccine are generally mild.

There is no aluminium, thiomersal, mercury, gelatin or porcine gelatin in the Quadrivalent Inactivated Influneza and Fluad Tetra vaccine used in the 2021/2022 campaign. 

In Fluad Tetra the adjuvant (ingredient) used is MF59. MF59 is mainly made from squalene oil – a natural oil found in humans, plants and animals. There is also a small amount of polysorbate-80. People who have had a reaction to vaccines or medication that contains polysorbate-80 should not get Fluad Tetra. 

There are very small amounts of gelatin/porcine gelatin in the Live Attenuated Influenza Vaccine (Fluenz) for children aged 2-17 years old. Gelatin is used as a stabiliser and is different from gelatin found in food as it is processed and broken down into small fragments. 

Read more on the use of gelatin in the vaccine from the Irish Council of Imams.

Read more about what is contained in the Quadrivalent Inactivated Influneza and Fluad Tetra vaccine from the HPRA website.

Read more about what is contained in the nasal flu vaccine from the HPRA website.

Read more about how well vaccines work on the Centers for Disease Control and Prevention website

All medicines, including flu vaccines, require licensing by the Health Products Regulatory Authority (HPRA) or the European Medicines Agency (EMA).

Any harmful effects should be reported to the HPRA.

Flu vaccine side effects

The most common side effects are mild and include soreness, redness or swelling where the injection was given. Headache, fever, aches, drowsiness and tiredness may occur. You may have mild sweating and shivering as your immune system responds to the vaccine. This is not flu and will pass in a day or so.

Serious side effects such as a severe allergic reaction are rare.

In very rare cases Guillain-Barré syndrome (GBS) has been reported (Guillain-Barré Syndrome is a condition that affects the nerves in the body. It causes nerve inflammation and can result in pain, numbness, muscle weakness and difficulty walking). However, the risk of GBS following flu is significantly greater than that following the flu vaccine.

When you should not get the flu vaccine

    You should not get the flu vaccine if you:
  • have had a severe allergic (anaphylaxis) reaction to a previous flu vaccine or any part of the vaccine.
  • are taking medicines called combination checkpoint inhibitors, for example, ipilimumab plus nivolumab
  • have severe neutropoenia (low levels of a type of white blood cell) 
  • are ill with a temperature greater than 38 degrees Celsius - you should wait until you are well before getting the vaccine.

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

For the children’s nasal flu vaccine, there are additional reasons where the nasal flu vaccine would not be advised. Read more on the flu vaccine for children aged 2 to 17.

The 2021 / 2022 flu vaccine

This year's seasonal flu vaccine contains protection against 4 strains of flu virus. These are recommended by the World Health Organization (WHO) as the strains most likely to be circulating this season.

The four strains are:

  • an A/Victoria/2570/2019 (H1N1)pdm09-like virus
  • an A/Cambodia/e0826360/2020 (H3N2)-like virus
  • a B/Washington/02/2019 (B/Victoria lineage)-like virus
  • a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

The 2021/2022 HSE seasonal vaccination programme will offer 3 vaccines

More information

This page was last updated on 23 September 2021