Side effects of vaccination

All immunizations can cause discomfort that are called adverse effects or more commonly side-effects. Most side-effects are a result of the activation of the immune system, which is the purpose of the immunization. These symptoms are usually the same for all vaccines:

• Fever >38°, chills, body aches

• Local symptoms at injection site

• Tiredness, feeling unwell, headache, stomach/intestinal symptoms

These symptoms usually arise within 24 hours of the vaccination and rarely last longer than 24-48 hours except for local symptoms and lymph node swellings (see below). Symptoms often arise more quickly after a repeat dose of the same vaccine. Local symptoms can be simple ache but sometimes include itching, redness or swelling. These symptoms often last longer than 24 hours, even up to a week. It is not necessary to report these symptoms to the primary health care or the institution that performed the immunization, or to the Icelandic Medicines Authority (IMA), unless they are unusually severe. Paracetamol or ibuprofen can be used in the package recommended doses for those individuals who can tolerate those medicines, if necessary to reduce discomfort after vaccination.

Lymph nodes nearest to the injection site, usually under the injected arm, are a well known but rare side effect related to the activation of the immune system. If they are more widespread it is advisable to contact a health care provider, for example in primary care, who will assess whether an examination or treatment is necessary and report to the IMA.

Possible side-effects of COVID-19 vaccines apart from immune activation:

These side-effects should be reported to the IMA in all cases because of the additional monitoring in effect for these new products. Be aware that connection to the vaccination has not been confirmed for all such symptoms but if occurrences are well documented it may be possible to confirm or refute a causal relationship with the vaccination. When causal relationships are confirmed it may be possible to define those who are at risk of such side-effects and plan for appropriate response or make additional recommendations regarding vaccination of such individuals.

Comirnaty/Pfizer BioNTech vaccine: (see product information)

• Anaphylaxis

   or other acute allergic symptoms

• Facial nerve palsy (Bell palsy)

• Pericarditis and myocarditis are now listed side effects, more common in males under age 30 than other people

• Other sudden, new onset symptoms that may be related to the vaccine

Spikevax/Moderna vaccine: (see product information)

• Anaphylaxis

   or other acute allergic symptoms

• Facial nerve palsy (Bell palsy)

• Pericarditis and myocarditis are now listed side effects, more common in males under age 30 than other people

• Other sudden, new onset symptoms that may be related to the vaccine

Astra Zeneca vaccine: (see product information)

• Anaphylaxis

   or other acute allergic symptoms

• Blood clots with low platelets (Thrombosis with Thrombocytopaenia Syndrome; TTS) – rare but believed truly related to vaccination although the mechanism is still unknown. New onset symptoms that should prompt an urgent medical assessment if arise within 14 days of vaccination include:

  • Difficulty breathing/dyspnoea

  • Sudden new and severe pain in the head, chest or abdomen

  • Pain and swelling of a limb other than the one injected with the vaccine, without preceding injury

  • Neurological symptoms such as blurry vision

  • Petechiae and purpurae/blood spots or bruises on the skin other than around the injection site

• Other sudden, new onset symptoms that may be related to the vaccine

Janssen vaccine: (see product information)

• Anaphylaxis or other acute allergic symptoms

• Blood clots with low platelets (Thrombosis with Thrombocytopaenia Syndrome; TTS) – rare but believed truly related to vaccination although the mechanism is still unknown. New onset symptoms that should prompt an urgent medical assessment if arise within 14 days of vaccination include:

  • Difficulty breathing/dyspnoea

  • Sudden new and severe pain in the head, chest or abdomen

  • Pain and swelling of a limb other than the one injected with the vaccine, without preceding injury

  • Neurological symptoms such as blurry vision

  • Petechiae and purpurae/blood spots or bruises on the skin other than around the injection site

• Other sudden, new onset symptoms that may be related to the vaccine
  
  

Notification to the Icelandic Medicines Authority:

Anyone can notify the IMA of a suspected adverse effect of a medicine, including vaccines. Family members or staff in long-term care facilities can send notifications on behalf of vaccinated inhabitants of such facilities. It is most important to notify the IMA if suspected side-effects are new (not included in the product information above), previously described but of uncertain incidence (according to the product information) or serious (requiring treatment beyond the simple fever reducing pain medicines discussed above). Notifications can be made to health care providers who then report to the IMA, by email or directly on the IMA website.