All vaccines are tested for safety and effectiveness before they can be used. The HSE only uses a vaccine if it meets the required standards of safety and effectiveness.
Most people will be able to safely get the vaccine. The person giving you the vaccine will be happy to answer any questions you have.
Who should not get the Janssen COVID-19 vaccine
Do not get the Janssen COVID-19 vaccine if you have:
- had a severe allergic reaction to any of the ingredients in the vaccine. This includes polysorbate 80. Read the European Medicines Agency's Janssen COVID-19 vaccine information to see the list of ingredients
- have had a severe allergic reaction to a previous dose of this vaccine or the AstraZeneca vaccine - this is because the Janssen and AstraZeneca vaccines are both viral vector vaccines
- have been told by a doctor that you should not have the AstraZeneca vaccine for medical reasons
- have had blood clots with low platelets after a previous dose of the AstraZeneca vaccine
Talk to your GP about the risks and benefits of getting this vaccine if:
- you have had a severe allergic reaction (anaphylaxis) in the past, including to any other vaccine or medication
- you have had thrombocytopenia in the past
You will need your platelet levels monitored after this vaccine if you have a history of immune thrombocytopenia.
If you are pregnant
This vaccine is not recommended if you are pregnant. You will be offered a different vaccine.
Janssen is a viral vector vaccine
The Janssen COVID-19 vaccine is a viral vector vaccine.
Work to develop COVID-19 vaccines moved much faster than usual to make them available as soon as possible.
Ingredients of the Janssen COVID-19 vaccine
The Janssen COVID-19 vaccine does not contain eggs, preservatives or latex.
For more information, read the European Medicines Agency's Janssen COVID-19 vaccine page.
This content was fact checked by vaccine experts working in Ireland.
Last updated: 23 December 2021 at 4.20pm