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Weak immune system and COVID-19 vaccines

It is important that you are vaccinated against COVID-19 if you have a weak immune system (immunosuppressed or immunocompromised).

Having a weak immune system puts you at higher risk of serious illness if you get COVID-19. Getting vaccinated will give you some protection against this.

Weak immune system list

Recommended COVID-19 vaccination

People with a weak immune system age 6 months and older are recommended to have:

  • 2 doses, 4 weeks apart, as your first round of COVID-19 vaccination
  • a third dose 8 weeks after this - only if advised by a specialist
  • seasonal booster doses, when they are being offered

How to get your vaccine

Vaccines will be given in hospital if you're an inpatient.

If you are 12 or older, you can also:

Children under 12

Children under 12 must go to a walk-in clinic. They cannot be vaccinated by your GP or pharmacy.

Go to the correct clinic for your child’s age group. The vaccine doses offered are different for young children.

Find a walk-in vaccination clinic for children

Third dose

COVID-19 vaccines may be less effective for you than other people.

If you have a weak immune system at the time of your first round of COVID-19 vaccination, you need 2 doses for your first round to give you better protection.

Your doctor may also recommend a third dose to give you better protection. Talk to your hospital team or GP if you have a weak immune system and may need a third dose.

When you should get a third dose

You should get a third dose 8 weeks after your second dose. But you can get it 4 weeks after your second dose if you need to be protected urgently.

If you had COVID-19 after your second dose

If your COVID-19 infection was more than 7 days after the second vaccine dose, you do not need to get a third dose. You should still get your booster dose when they are being offered.

If you get COVID-19 within 7 days of your second dose, you should get a third dose 4 to 8 weeks after your COVID-19 infection. You only need this if your doctor or hospital team recommends it.

Weak immune system list

Follow the recommended COVID-19 vaccination on this page if you have a weak immune system.

Check the list of conditions or treatments that can lead to a weak immune system.

Your GP or hospital consultant will confirm if you should get a third dose or booster.

If you have been recently diagnosed with a weak immune system, your doctor will need to refer you for COVID-19 vaccination.

Cancer

Cancer patients affected include people who are:

  • receiving or within 6 weeks of receiving systemic cytotoxic chemotherapy, targeted therapy, monoclonal antibodies or immunotherapies
  • receiving treatment or pending treatment for a haematological cancer
  • within 5 years of having had treatment for haematological cancer
  • undergoing or within 6 weeks of surgery or radiotherapy for lung or head and neck cancer
  • advanced metastatic cancer

Haematological cancer includes:

  • leukaemia
  • lymphomas
  • blood dyscrasias
  • other malignant neoplasms affecting the bone marrow or lymphatic systems
Chronic kidney disease

People who have chronic kidney disease and:

  • are on dialysis, or their eGFR is less than 15ml/min
  • eGFR is less than 30ml/min
Transplantation

People who have:

  • been listed for solid organ or haematopoietic stem cell transplant (HSCT)
  • had a solid organ transplant at any time
  • had a HSCT in the past 12 months
Genetic diseases

People who have:

  • autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED)
  • inborn errors in the interferon pathway
  • some B and T cell deficiencies
Treatment

People being treated with:

  • Cyclophosphamide
  • Rituximab
  • Alemtuzumab
  • Cladribine
  • Ocrelizumab
High dose systemic steroids

The following doses of prednisolone (or equivalent dose of other glucocorticoid) are likely to be immunosuppressive:

  • adults and children over 10kg: ≥40mg/day for more than 1 week, or ≥20mg/day for 2 weeks or longer
  • children under 10kg: 2mg/kg/day for 2 weeks or longer
HIV

People living with HIV not on treatment, or who have CD4 count less than 200/10-6L for adults

Safety and side effects of COVID-19 vaccines

All COVID-19 vaccines used in Ireland are approved by the European Medicines Agency (EMA)

Safety and side effects of COVID-19 vaccines used in Ireland

Staying safe from COVID-19

Avoid situations where you could pick up the virus, such as crowded areas.

Everyone you live with who can get vaccinated should be up to date with their COVID -19 vaccination. This will help to protect both you and them from COVID-19.

How COVID-19 affects people with a weak immune system, including information on steroids

Page last reviewed: 6 September 2024