Safety - Janssen COVID-19 vaccine

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
  • 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

Non-urgent advice: Talk to your doctor before getting your COVID-19 vaccine if

you have had an immediate or severe allergic reaction:

  • to any vaccines or medications
  • for reasons that you do not know the cause for

This vaccine is not recommended if you are pregnant. You will be offered a different vaccine. Talk to your obstetrician or GP about getting your COVID-19 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.

Read about COVID-19 vaccine development

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: 2 July 2021 at 10.35am