Moderna COVID-19 vaccine leaflet

Version 10

12 October 2021

This is a web-friendly version of the patient information leaflet. You can also download this leaflet as a PDF: Information leaflet about the COVID-19 Moderna vaccine (PDF, 412 KB, 12 pages)

About this leaflet

This leaflet tells you about the COVID-19 (coronavirus) vaccine. It tells you about:

  • what COVID-19 is
  • what the COVID-19 vaccine is
  • who should get the vaccine
  • why it is important to get the vaccine
  • who should not get it and who should delay getting it
  • vaccine safety and side effects
  • where you can get more information

Please read this leaflet carefully. You can also talk to a healthcare professional, like your GP (Doctor) or Pharmacist, about the vaccine.

What is COVID-19?

COVID-19 is an illness that can affect your lungs and airways, and sometimes other parts of your body. It’s caused by a virus called coronavirus.

COVID-19 is highly infectious. It spreads through the air through droplets produced when people cough or sneeze, or when they touch surfaces where the droplets have landed and then touch their eyes, nose or mouth.

COVID-19 can cause serious illness, hospitalisation and even death.

The most common symptoms of COVID-19 are:

  • a fever (high temperature of 38 degrees Celsius or above) - including having chills
  • dry cough
  • fatigue

You may not have all of these symptoms or you may just feel generally less well than usual. It can take up to 14 days for symptoms to show. They can be similar to symptoms of cold or flu.

If you have any symptoms of COVID-19, self-isolate (stay in your room) and get a COVID-19 test.

For more information on COVID-19, please visit or call HSELive on 1800 700 700.

Who is most at risk from COVID-19?

Older people and people with certain health conditions have a higher risk of getting seriously ill if they get COVID-19.

What is the COVID-19 vaccine?

A vaccine is a substance that should improve immunity (protection) to a particular disease. The COVID-19 vaccine will offer you protection from COVID-19. If people are vaccinated, it should also reduce the numbers who become seriously ill or even die from COVID-19 in our community.

Vaccines teach your immune system how to protect you from diseases. It is much safer for your immune system to learn how to protect you through vaccination than by getting COVID-19.

Who should get the vaccine?

Find out who can get a COVID-19 vaccine at

While it is up to you to decide to get the vaccine, the HSE, the World Health Organization and the Department of Health strongly recommend that you do so as soon as it is offered to you.

You will need to read this leaflet and the manufacturer’s Patient Information Leaflet before you get the vaccine. You can find the manufacturer’s Patient Information Leaflet on

You can also talk to a healthcare professional in advance. If you decide to get the vaccine, you will give your consent which will be recorded.

The HSE is offering the vaccine free of charge.

Why is it important to get the COVID-19 vaccine?

Getting a COVID-19 vaccine should reduce your risk of getting COVID-19 and protect you from serious complications of the illness. Our aim in offering the vaccine to the population is to protect people and reduce the illness and deaths caused by this virus.

I already had COVID-19, so do I need to get the vaccine?

Yes. Even if you have already had COVID-19, you could still get it again.

The vaccine will reduce your risk of getting COVID-19 again. Even if you do get COVID-19 again, the vaccine can reduce the seriousness of your symptoms.

I have COVID-19 now, should I get the vaccine?

No. You should delay getting vaccinated until you recover from COVID-19.

Do this for:

  • at least four weeks after you first notice symptoms or
  • four weeks since you tested positive for COVID-19

Getting the vaccine

Who is my vaccinator?

Your vaccinator is the person who gives you your vaccine. They are trained by the HSE to give COVID-19 vaccines.

Can the COVID-19 vaccine give you COVID-19?

No. The COVID-19 vaccine cannot give you COVID-19. It is possible to have caught COVID-19 before getting your vaccine and not realise you have the symptoms until after your vaccination appointment.

If you have any symptoms of COVID-19, it is important to self-isolate (stay in your room) and arrange a free test to find out if you have COVID-19.

If you have a fever which starts more than two days after you get the vaccine, or lasts longer than two days, you should self-isolate and get a COVID-19 test.

If you have COVID-19 symptoms after the first dose, you still need to have the second dose. While you may get some protection from the first dose, having the second dose will give you the best protection against the virus.

Should I get the COVID-19 vaccine if I have a high temperature?

No. You should delay getting the vaccine if you have a fever (temperature of 38 degrees Celsius or above), until you feel better.

Should I get the vaccine if pregnant, trying to get pregnant or breastfeeding?

You should get a COVID-19 vaccine to protect yourself from the virus if you're:

  • pregnant
  • trying for a baby or might get pregnant in the future
  • Breastfeeding

Most pregnant women who get the virus get mild to moderate symptoms. They give birth as planned and the risk of passing on COVID-19 to their baby is low.

But you are more likely to get very unwell and need treatment in intensive care than a woman who is not pregnant. The virus may also cause complications for your baby.

But COVID-19 vaccines are still new. We’re still learning about them. If you are pregnant, you should talk to your Obstetrician or GP (Doctor) about getting the COVID-19 vaccine and read more at

What vaccine am I being offered?

The vaccine we are offering you is called Spikevax. The vaccine is manufactured by Moderna.

This mRNA vaccine teaches your body how to make a protein that will trigger an immune response, without using the live virus that causes COVID-19.

Your body then makes antibodies that help fight the infection if the COVID-19 virus enters your body in the future.

Is the vaccine safe?

The HSE only uses vaccines when they meet the required standards of safety and effectiveness.

While the work to develop COVID-19 vaccines has moved much faster than usual, the vaccine we are offering you has gone through all the usual steps needed to develop and approve a safe and effective vaccine.

In order to be approved for use, the COVID-19 vaccine went through all the clinical trials and safety checks all other licensed medicines go through, following international standards of safety.

The vaccine we are offering you is called Spikevax. It is manufactured by COVID-19 Vaccine Moderna.

It has:

  • been tested with thousands of people as part of clinical trials
  • met strict standards of safety, quality and effectiveness, and been approved and licensed by regulators. For Ireland, the regulator is the European Medicines Agency (EMA) – visit for more information

How is the COVID-19 vaccine given?

The COVID-19 vaccine is given as an injection into your upper arm. It will only take a few minutes.

How many doses of the COVID-19 vaccine will I need?

You will need two doses of the COVID-19 vaccine to get the best protection. You need to get the second dose 28 days (four full weeks) after the first dose.

What are the side effects of the vaccine?

Like all medicines, vaccines can cause side effects. Most of these are mild to moderate, short-term, and not everyone gets them.

More than one in 10 people may experience:

  • feeling tired
  • tenderness, swelling, redness or itching in the arm where they have had the vaccine injection
  • headache
  • swollen lymph glands under the arm where they had the injection
  • muscle pain
  • joint pain
  • nausea or vomiting
  • fever (temperature of 38 degrees Celsius or above)

Bell’s palsy is a rare side effect seen in more than 1 in 10,000 people.

Rarely, people who have had facial fillers may develop swelling of their face. This is seen in more than 1 in 10,000 people.

Serious side effects, like a severe allergic reaction, are extremely rare, seen in approximately 2–3 in a million people. Your vaccinator is trained to treat very rare serious allergic reactions.

Extremely rarely, people may develop Erythema Multiforme, a skin reaction that causes red spots or patches on the skin, that may look like a target or "bulls-eye" with a dark red centre surrounded by paler red rings.

Very rarely, people may develop myocarditis and pericarditis after getting the Moderna (Spikevax) vaccine. Myocarditis and pericarditis are inflammatory heart conditions. The risk of these very rare conditions is higher in younger men.

Myocarditis was reported  in about 1 in 1,000,000 vaccine doses. However, data from the United States estimates that, after the second dose of the vaccine, the risk of myocarditis is higher for younger men. The estimated risk is:

  • 1 in 16,000 in young men aged 12−17 
  • 1 in 20,000 in young men aged 18−24 years
  • 1 in 100,000 in young women aged 12-17

Pericarditis was reported in about 1 in 1,000,000 vaccine doses. 

These conditions are more likely to occur after the second dose and mostly happen within 14 days of getting the vaccine. 

The COVID-19 vaccine has gone through the same clinical trials and safety checks as all other licensed vaccines, however the vaccine is new and long-term side effect information is limited.

As more people in Ireland and around the world get this vaccine, more information on side effects may become available. The HSE will update this information regularly on our website, and if necessary, will update the information leaflets given to people at their first or second dose of the vaccine.

Fever after the vaccine

It’s quite common to develop a fever after a vaccination. Usually, this happens within two days (48 hours) of getting the vaccine, and it goes away within two days.

You are more likely to get a fever after your second dose of the vaccine.

If you feel uncomfortable, take paracetamol or ibuprofen as directed on the box or leaflet. If you are concerned, please seek medical advice.

Symptoms of myocarditis and pericarditis

Myocarditis and pericarditis are conditions that cause inflammation of the heart. Even though the risk of these conditions is very low, you should know the signs to look out for. Get medical help if you get any of these symptoms after your Moderna (Spikevax)vaccine:

- breathlessness

- palpitations (a forceful heartbeat that may be irregular)

- chest pain

Are there some people who should not get the COVID-19 vaccine?

Yes. You should not get the Moderna (Spikevax) COVID-19 vaccine if:

  • you have had a severe allergic reaction to any of the ingredients in the vaccine (including polyethylene glycol or PEG). Read the manufacturer’s Patient Information Leaflet to see the list of ingredients.
  • you have had a severe allergic reaction to a previous dose of the vaccine or the Pfizer/BioNTech (Comirnaty) vaccine.
  • you have had a severe allergic reaction after Trometamol (a contrast dye used in MRI radiological studies)
  • you have been told by a doctor that you should not have the Pfizer/BioNTech (Comirnaty) vaccine or the Moderna (Spikevax) COVID-19 vaccine
  • you had myocarditis after a previous dose of this vaccine or the Pfizer/BioNtech (Comirnaty) COVID-19 vaccine.

Talk to your Doctor before getting the COVID-19 vaccine if you:

  • have had an severe allergic reaction (anaphylaxis) in the past, including to any other vaccine or medication.
  • had pericarditis after a previous dose of this vaccine or the Pfizer/BioNTech (Comirnaty) vaccine COVID-19 vaccine

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 at your appointment for the vaccine.

They will also give you an aftercare advice leaflet, and a vaccine record card showing the name and batch number of the vaccine you have been given.

How long does it take the vaccine to work?

After having both doses of the COVID-19 vaccine, most people will have immunity. This means they will be protected against COVID-19.

It takes 14 days after getting the second dose for it to work.

There is a chance you might still get COVID-19, even if you have the vaccine.

Does the vaccine work in everyone?

Worldwide, vaccines save at least 2 to 3 million lives each year, and protect many more from lifelong illnesses. Millions of people have now received COVID-19 vaccines all over the world.

There’s strong, reliable evidence that COVID-19 vaccines greatly reduce your risk of getting COVID-19. They’re highly effective at preventing deaths and serious illness with COVID-19.

If you have a weakened immune system, there is no extra risk in taking the vaccine but it may not work as well for you.

When I get the vaccine, does that mean I won’t spread COVID-19 to others?

We do not know yet if having the vaccine stops you spreading the COVID-19 virus to others. You should continue to follow public health advice on how to stop the spread of the virus.

In particular, you still need to:

  • wear a face covering where advised
  • wash your hands regularly
  • stay at home if you have any symptoms of COVID-19

Thank you for protecting yourself and others.

How long does immunity last from the vaccine?

We do not know yet how long immunity will last. Clinical trials are ongoing to find this out.

More information

For more information, read the manufacturer’s Patient Information Leaflet. This will be printed for you on the day you get your vaccine, or you can find it on

You can also talk to a health professional, like your GP (Doctor), Pharmacist or healthcare team.

You can visit the HSE website at or call HSELive on 1800 700 700.

For more information on the COVID-19 vaccine, including materials in other formats and translation support, visit

How do I report side effects?

As with all vaccines, you can report suspected side effects to the Health Products Regulatory Authority (HPRA).

The HPRA is the regulatory authority in the Republic of Ireland for medicines, medical devices and other health products. As part of its role in the safety monitoring of medicines, the HPRA operates a system through which healthcare professionals or members of the public can report any suspected adverse reactions (side effects) associated with medicines and vaccines which have occurred in Ireland.

The HPRA strongly encourages reporting of suspected adverse reactions (side effects) associated with COVID-19 vaccines to support continuous monitoring of their safe and effective use. To report a suspected adverse reaction to the COVID-19 vaccine, please visit

You can also ask your doctor or a family member to report this for you. As much information as is known should be provided, and where possible, the vaccine batch number should be included.

The HPRA cannot provide clinical advice on individual cases. Members of the public should contact their healthcare professional (their Doctor or Pharmacist) with any medical concerns they may have.

Your personal information

In order to administer the vaccine safely and to record all the necessary information to monitor and manage the vaccine, the HSE will be processing your personal information. All information processed by the HSE will be in accordance to the general laws and in particular the General Data Protection Regulation (GDPR) which came into force in 2018.

The processing of your data will be lawful and fair. It will only be processed for the specific purpose to manage the vaccinations. The principle of Data Minimisation has been applied. This means that only data that is necessary to identify you, book your appointment, record your vaccination and monitor its effects is being recorded.

You have the following rights as a data subject under the GDPR in respect of your personal data that are processed.

  • Request information on and access to your personal data (commonly known as a ‘data subject access request’). This enables you to receive a copy of the personal data we hold about you and to check that we are lawfully processing it.
  • Request correction of the personal data that we hold about you. This enables you to have any incomplete or inaccurate information we hold about you corrected.
  • Request erasure of your personal data. This enables you to ask us to delete or remove personal data where there is no good reason for us continuing to process it. You also have the right to ask us to delete or remove your personal information where you have exercised your right to object to processing.
  • Object to processing of your personal data.

More information is available at

Page last reviewed: 9 August 2021

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