Vaccines are the safest way to prevent infectious diseases. They teach your immune system (your body's natural defences) how to protect you from a specific virus.
Some people at higher risk should get seasonal booster doses to extend the protection of COVID-19 vaccines. We do not know yet how long immunity will last after getting a booster. Trials are happening now to find this out.
Bivalent (adapted) vaccines
The European Medicines Agency (EMA) and National Immunisation Advisory Committee (NIAC) have recommended adapted mRNA COVID-19 vaccines as booster doses.
These adapted vaccines work in the same way as the original Pfizer and Moderna COVID-19 vaccines.
While all previous vaccines offer protection against COVID-19, the adapted vaccines are expected to give wider protection against COVID-19 variants. This includes the Omicron variant.
Doses and immunity
The doses needed for COVID-19 vaccines used in Ireland are listed below.
What does ‘first round of COVID-19 vaccination’ mean?
When we say ‘first round of COVID-19 vaccination’ we mean your dose 1 and dose 2 if you got AstraZeneca, Moderna or Pfizer. Or your single dose if you got the Janssen vaccine.
If you have a weak immune system, you should have been offered an ‘additional dose’ to give you better protection. This is because your immune system may not respond as well to vaccination. You will still need your booster doses after this additional dose.
Getting different vaccines
You may be offered a different vaccine for your second dose or booster dose to the one you originally had. For example, you may get a booster dose of the Pfizer vaccine after getting the AstraZeneca vaccine for your first 2 doses.
So far, there have been no concerns about serious side effects with this option. Some side effects may be more common if you get a different vaccine from the one you got previously. For example, pain, fever, headache and fatigue. These side effects do not last long.
Studies have found that the immune response after getting different vaccines may be as good as getting the same vaccine. In some cases, it can be better.
People can choose this option because it has been advised by the National Immunisation Advisory Committee (NIAC ) in Ireland. It is not yet approved by the European Medicines Agency (EMA). At the moment, the EMA has only approved the use of 2 doses of the same vaccine for your first round of vaccination.
Vaccine types
The different types of COVID-19 vaccines used in Ireland are:
- mRNA - Pfizer/BioNTech and Moderna
- viral vector - AstraZeneca and Janssen
- protein subunit - Novavax and Vidprevtyn Beta
Read about the different vaccine types - mRNA, protein subunit and how they work
Side effects and safety
Like all medicines, COVID-19 vaccines can cause side effects. Most of these are mild to moderate and do not last long.
Protection from COVID-19
Anyone who gets COVID-19 can become seriously ill or have complications. Getting vaccinated is the best way to protect yourself and others.
You can still get COVID-19 after vaccination. But being vaccinated can reduce how serious your symptoms will be.
Continue to follow public health advice on how to stop the spread of COVID-19. For example, washing your hands properly and often.
This content was fact checked by vaccine experts working in Ireland.