​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 blood clots and low blood platelet counts following vaccination with the mRNA vaccines

On 20 April 2021, the European Medicines Agency (EMA) announced that it had received reports of cases of blood clots combined with low blood platelet counts concerning the mRNA vaccines. Worldwide, approximately 200 million doses of the Comirnaty (BioNTech/Pfizer) vaccine and approximately 80 million doses of the Moderna COVID-19 Vaccine have been administered. There have been 25 cases of blood clots combined with low blood platelet counts following vaccination with the Comirnaty (BioNTech/Pfizer) vaccine, and five cases of blood clots combined with low blood platelet counts following vaccination with Moderna's vaccine. Two of these reports are from Norway.

“Relative to the number of doses that have been administered, these are very low figures. The information that has come to light so far provides no basis for saying that this is the same combination of symptoms as we have seen following vaccination with the Vaxzevria vaccine. Additional information has been requested for the two reports in order to carry out a more detailed assessment," says consultant Sigurd Hortemo.

The incidence of blood clots increases with age and low blood platelet counts are associated with many chronic diseases, but it is rare for them to occur in combination.

Expert group investigating in Norway

The European Medicines Agency (EMA) has concluded that there is a link with cases of rare and very severe blood clots combined with low blood platelet counts and bleeding with the viral vector-based Vaxrevria (AstraZeneca) and Janssen COVID-19 vaccines. It is the Norwegian Government which makes the final decision regarding the use of these vaccines in Norway. The current suspension of use of the Vaxrevria vaccine will remain in place until further notice, and the introduction of the Janssen vaccine has been postponed. An expert group has been set up with a deadline of 10 May 2021 to submit recommendations to the Norwegian Government regarding how these EU/EEA-approved vaccines should be used in Norway.

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What suspected adverse reactions should be reported?

Most of the reports submitted to date concern common adverse and expected reactions, such as pain at the injection site, headache, general malaise with fever, fatigue, nausea and pain in the body. These adverse reactions last around 2-3 days and are known from the studies which formed the basis for the vaccine authorisations.

It is particularly important to report adverse reactions which are not referred to in the patient information leaflet or which are considered to be very serious.

It is not necessary to report transient and common adverse reactions which are already known, such as fatigue, headache, nausea, muscle and joint pain, chills and fever. Health professionals are obliged to report suspected serious adverse reactions to vaccines.
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 (lack of effect based on what the vaccine is expected to provide protection against)

How to report adverse reactions

Health care professionals should report adverse reactions 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.
Click here if you are a patient and wish to report adverse reactions

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.

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