​The reports of adverse reactions that we have received do not provide a basis for revising the current recommendations regarding vaccination with the Comirnaty (BioNTech/Pfizer) and Moderna COVID-19 vaccines.

Click here to go to an overview of reports of suspected adverse reactions (the adverse reactions report)

Reports of serious events are assessed first. The figures therefore do not give a true picture of the distribution between serious and non-serious events.

Reports of acute pericarditis and myocarditis

A total of 17 cases of acute pericarditis (inflammation of the lining around the heart) have been reported as suspected adverse reactions, 14 following vaccination with the Comirnaty COVID-19 vaccine, two following vaccination with Moderna and one following vaccination with Vaxzevria (AstraZeneca). Four cases of myocarditis (inflammation of the heart muscle) have been reported following vaccination with Comirnaty. At the time the reports were submitted, the patients were recovering.

It is estimated that pericarditis is the cause of approximately 5% of all referrals to accident and emergency departments with chest pain. Pericarditis occurs more frequently in men than in women. The most common cause of pericarditis is viral infection, and a number of reports have indicated that COVID-19 may also lead to pericarditis in some cases. Pericarditis has a good prognosis.

Myocarditis is an inflammation of the heart muscle and can for example occur in connection with infections or the taking of medication. It is a rare condition. Most cases are mild and do not require treatment, but the condition can also lead to serious consequences in the form of impaired heart function and the need to hospitalise the patient.

"It is not yet clear whether these conditions can be linked to the vaccine. We are currently investigating whether the conditions occur more frequently in those who have been vaccinated than those who have not," says Steinar Madsen, Medical Director of the Norwegian Medicines Agency.

Anyone who experiences worrying breathlessness or chest pain should seek a doctor, regardless of whether or not they have been vaccinated.

The Norwegian Medicines Agency has previously described cases of pericarditis that have been reported as suspected adverse reactions following vaccination.

Common and expected adverse reactions

Most adverse reactions following COVID-19 vaccination, regardless of the type of vaccine used, concern known and transient adverse reactions such as:

  • headache
  • fatigue
  • malaise
  • fever
  • nausea
  • pain in the body

These usually appear on the first or second day after vaccination and last around 2-3 days. Most people tolerate these transient adverse reactions well, while others experience significant discomfort during the first few days after vaccination. These suspected adverse reactions are in line with what is described in the product information.

How to report adverse reactions

Health professionals are obliged to report suspected serious adverse reactions following vaccination. It is not necessary for the causal relationship to be known; suspicion is sufficient to report an incident.

It is particularly important to report reactions where any of the following are suspected:

  • new adverse reactions not referred to in the patient information leaflet
  • unexpected adverse reactions
  • serious adverse reactions
  • vaccine failure (severe COVID-19 following full vaccination)

If a person becomes seriously ill with COVID-19 one to two weeks following the completion of vaccination, this is considered to constitute a possible vaccine failure. Severe or critical cases (COVID-19 symptoms and disease) in persons who have been fully vaccinated must be reported as a suspected adverse reaction via melde.no.

The general population can report adverse reactions via helsenorge.no, but you should consult a doctor or other health professional in the case of suspected serious or unexpected adverse reactions following vaccination. You do not need to report a possible adverse reaction yourself if a health professional has already reported the reaction.

International cooperation 

Reports of adverse reactions following vaccination are followed up by the Norwegian Medicines Agency in partnership with the Norwegian Institute of Public Health and the regional medicines information and pharmacovigilance centres (RELIS). The Norwegian Medicines Agency is responsible for the National ADR Register, and exchanges adverse reaction data with the European Medicines Agency (EMA) and the World Health Organization (WHO). This provides us with a better basis for assessing causation, identifying new adverse reactions and implementing measures to safeguard patient safety.

​Fant du det du lette etter?