This page contains information about the side-effects of the COVID-19 vaccines made by Pfizer/BioNTech, Moderna, AstraZeneca and Janssen. 

You can report side-effects of the COVID-19 vaccine (in Dutch) to the Pharmacovigilance Centre Lareb.

If you experience serious symptoms after vaccination, contact your GP.

Most common side-effects of the COVID-19 vaccines

Side-effects such as fever, headache and tiredness occur after vaccination with COVID-19 vaccines in a significant proportion of those who are vaccinated. Side-effects such as muscle pain, joint pain, chills, nausea and vomiting may also occur after vaccination with COVID-19 vaccines. These symptoms start within a day or so after vaccination and go away by themselves, but can be unpleasant. The number of people who experience these side-effects after vaccination differs depending on which vaccine they received. Women and young people are more likely to have side-effects after vaccination. See the questionnaire survey (in Dutch) by Lareb.

For a complete overview of the possible side-effects, see the vaccine package leaflets.

Very rare and serious side-effect of Janssen and AstraZeneca vaccines

In very rare cases, more serious side-effects may also occur. These symptoms are very uncommon. In the context of the AstraZeneca and Janssen vaccines, this can involve a combination of blood clots (thrombosis) with low levels of blood platelets (thrombocytopenia). This side-effect is referred to as thrombosis with thrombocytopenia syndrome (TTS).

Since the risk of this rare side-effect is very low, these vaccines are deployed for some specific groups. The AstraZeneca vaccine is only given to people born in 1960 or before. The Health Council of the Netherlands advised using the Janssen vaccine in situations in which the advantage of a single vaccination (rather than 2 doses) is very significant. 

It is important to contact medical professionals immediately if you develop these symptoms after vaccination with Janssen or AstraZeneca:

  • shortness of breath;
  • pain in the chest or abdomen;
  • swelling or a cold feeling in an arm or leg;
  • severe or worsening headache or blurred vision;
  • persistent bruising;
  • multiple tiny blood spots: red or purple dots or blisters under the skin.

If these symptoms do occur, they are usually seen within three weeks after vaccination.

More information is available on the page about AstraZeneca side-effects. The website of the Dutch Medicines Agency (CBG-MEB) also offers more information about AstraZeneca and Janssen (in Dutch).

Myocarditis and pericarditis

In very rare cases, inflammatory diseases of the heart may occur following vaccination with Pfizer or Moderna: myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the outer lining of the heart). This has been established by the European Medicines Agency (EMA) after reviewing reports from countries within Europe and beyond.

The reports indicate that the cases of myocarditis and pericarditis mostly started within the first fourteen days after vaccination, and were more likely to occur after the second vaccination than after the first. Symptoms include shortness of breath, chest pain and a forceful heartbeat that may sometimes be irregular. The symptoms can vary significantly and usually improve on their own or can be treated effectively with medication. People who have these symptoms should consult their doctor.

The incidence of myocarditis and pericarditis ranges between 1 and 10 in 100,000 people per year. The risk of side-effects also depends on the age of the person and on the vaccine. These inflammatory conditions are seen most often in boys and younger men between 12 and 30 years old. Although these side-effects are still rare, they are slightly more likely to occur after Moderna than after Pfizer. In people over 12, myocarditis is even more likely to occur after a COVID-19 infection. It can also occur after another viral infection or in the context of an immune disease. Myocarditis after mRNA vaccination usually (> 90%) goes away within a few days, either spontaneously or with treatment. If symptoms of myocarditis occur, always contact a doctor. More information for the Netherlands is available in Dutch on the websites of the Medicines Evaluation Board (CBG-MEB) and Pharmacovigilance Centre Lareb (in Dutch).

A review of seven cases is presented in this preprint.

Allergies

It is possible for a severe allergic reaction (anaphylactic shock) to occur immediately after vaccination. The vaccine has been administered to many, many people all over the world, and anaphylactic shock has been very rare.

RIVM is currently working with the Dutch Society for Allergology and Clinical Immunology (NVvAKI) on a solution for administering vaccinations under medical supervision. More information about this will be available soon.

If you have ever had a severe allergic reaction or breathing problems after a vaccination, always report this to the doctor at the vaccination site. 
After vaccination, everyone will remain at the vaccination site for 15 minutes longer so that any allergic reactions can be treated immediately.  

Trial dose possible?

You cannot receive a trial dose of the vaccines.  However, everyone who receives a vaccine is monitored for 15 minutes after vaccination. If an allergic reaction does occur, it can be treated immediately.

Medications for side-effects

You can take paracetamol to relieve the symptoms. Do not take more than the amount stated in the paracetamol package leaflet. If you are concerned even so, you can contact your family doctor.

Fever after vaccination against COVID-19

If you develop a fever within 48 hours after receiving the vaccination, it is likely that the fever is a side-effect of the vaccination. In that case, it is best to stay home yourself, but your household members do not have to stay home. Do you have a fever and other symptoms that could indicate COVID-19?  More information about symptoms, testing and quarantine is available on our webpages the disease COVID-19 and COVID-19 quarantine and isolation

Death after vaccination

If someone dies after a vaccination, the death is reported to Lareb. An overview of these reports is published on the Lareb website (in Dutch). An investigation then takes place to determine the cause and whether there is a direct link between the vaccination, any possible side-effects and the person’s death. The European Medicines Agency (EMA) monitors reports of side-effects and deaths from all countries. The EMA publishes a monthly report on these figures. 

Study on side-effects of COVID-19 vaccination

As of 1 February 2021, the Pharmacovigilance Centre Lareb has started actively monitoring side-effects after COVID-19 vaccination. In this study, vaccinated people will be sent 7 questionnaires over a period of 6 months. This will provide more information about which side-effects occur, how often they occur and how they develop. People can sign up for this study within 48 hours of their first COVID-19 vaccination or after making an appointment to get their first vaccination.