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Weak immune system and COVID-19 vaccines

You should get a COVID-19 vaccine 2 times a year if you have a weak immune system.

Free COVID-19 vaccines are available in spring and autumn.

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

Contact your GP or healthcare team if you are not sure if you need a COVID-19 vaccine.

If you never had a COVID-19 vaccine

People with a weak immune system who never had the COVID-19 vaccine before need 2 doses of the vaccine.

The doses are usually:

  • 4 weeks apart for people age 5 and older
  • 8 weeks apart for babies and children age 6 months to 4 years

You may get a third dose after 8 weeks if a specialist advises you to.

If you get COVID-19, wait at least 4 weeks after the infection before getting vaccinated for the first time.

How to get a COVID-19 vaccine

Pregnant and weak immune system

If you are pregnant and have a weak immune system you should get vaccinated.

Your GP or healthcare team can advise you about the doses you need.

COVID-19 vaccination in pregnancy

Safety and side effects of COVID-19 vaccines

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

Page last reviewed: 21/09/2026
Next review due: 21/09/2029