Anaphylaxis and COVID-19: Summary information for health care professionals

On this page

• Overview
• Symptoms of anaphylaxis
• Symptoms of anaphylaxis in infants and young children
• Risk factors for severe anaphylaxis
• How anaphylaxis should be managed
• What happens after a case of anaphylaxis is identified following vaccination
• Additional resources
  • Anaphylaxis management
  • COVID-19 vaccines

Overview

Anaphylaxis is a severe allergic reaction and a medical emergency. As with any medicines and vaccines, allergic reactions are very rare but can occur. The estimated historical frequency of anaphylaxis is about 1.3 episodes per million doses of vaccine administered. Anaphylaxis can be easily recognized and prompt treatment improves outcomes.

Quick recognition and management can be life saving. The progression and severity can be difficult to predict. Every vaccine provider should be familiar with the signs and symptoms of anaphylaxis and be prepared to act quickly. Anaphylaxis management kits should be readily available wherever vaccines are administered.

Advance preparation for emergency management of anaphylaxis is essential. It is recommended that vaccine providers develop, post, and regularly rehearse a written anaphylaxis emergency management protocol. Protocols should specify the necessary emergency equipment, drugs and dosages, and medical personnel necessary to safely and effectively manage anaphylaxis.

Symptoms of anaphylaxis

Symptoms of anaphylaxis can start within minutes of exposure to an allergen (such as a vaccine ingredient).

Symptoms vary from person to person. The same person can have different symptoms each time they have an allergic reaction.

Symptoms of a severe allergic reaction can include any of the following:

• Skin (most common): hives, swelling (face, lips, tongue, causing throat tightness, hoarse voice or trouble swallowing), itching, warmth, redness
• Respiratory: coughing, wheezing, shortness of breath, chest pain or tightness, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing)
• Gastrointestinal: intense nausea, severe abdominal pain or cramps, vomiting, diarrhea
• Cardiovascular: rapid heart rate, low blood pressure, fainting, dizziness or light-headedness - shock and cardiac arrest are exceptionally rare
• Other: anxiety, sense of doom (the feeling that something bad is about to happen)

Anaphylaxis usually involves two or more body systems. Isolated respiratory or gastrointestinal symptoms are rare.

Symptoms of anaphylaxis in infants and young children

It may be challenging to identify anaphylaxis in infants and young children because they are unable to describe their symptoms. Behavioural changes (e.g. irritability and inconsolable crying) should be watched for. Infants may present with:

• Skin: hives, flushing, swelling of the face
  • For all children, including infants, skin symptoms are the most common overall of any body system affected.
• Respiratory: coughing, wheezing, dyspnea
• Gastrointestinal: Vomiting (including persistent vomiting)
• Cardiovascular: rapid heart rate
• Non-specific signs and symptoms:
  • Sudden quietness or sleepiness, drooling, incontinence and behavioural changes such as inconsolable crying and irritability. Behavioural symptoms can occur, such as those listed previously, however context is important as changes in behavior are non-specific and can be common in this age group.

Risk factors for severe anaphylaxis

Anaphylaxis is a rare, acute and severe allergic reaction that can be triggered by allergens such as food, medications, or vaccines. Risk factors for increased severity of anaphylactic events include:

• Very young or old age
• Pregnancy
• Severe or uncontrolled asthma
• Cardiovascular disease
• Chronic obstructive pulmonary disease
• Systemic mastocytosis (a condition resulting in a build up of mast cells in the body)
• Concurrent use of certain medications (e.g., angiotensin-converting enzyme [ACE] inhibitors and beta-blockers)

How anaphylaxis should be managed

Steps for basic management of anaphylaxis in a community setting:

Death can occur within minutes. Rapid intervention, including administration of Epinephrine, is extremely important. Steps 1 to 4 should be done immediately and simultaneously.

1. Direct someone to call 9-1-1 (where available) or emergency medical services.
2. Assess airway, breathing, circulation, mental status, skin, and body weight. Secure an oral airway if necessary
   • Airway: look specifically at lips, tongue and throat for swelling.
3. Place individual on his/her back and elevate lower extremities. The client should remain in this position. Exceptions include:
   • If in respiratory distress, place in a position of comfort (elevate head and chest).
   • If vomiting or unconscious, place lying on the patient's side.
   • If pregnant, place lying down on their left side.
4. Inject epinephrine. There are no contraindications to the use of epinephrine for anyone.
   • Dose: 0.01 mg/kg body weight of 1:1000 (1 mg/mL) solution, to a maximum total dose of 0.5 mg.
     • Weight is the preferred method for dose calculation. If unknown, age can be used as a guide (Table 4 in the Canadian Immunization Guide: Dosage of intramuscular epinephrine solution, by age or weight). This table should be included as part of the anaphylaxis management kit for use as a quick reference.
     • For infants weighing less than 5 kg, the dose of epinephrine should be determined by weight, if possible.
   • Route: intramuscular (IM) in mid-anterolateral thigh.
   • Repeat every 5-15 minutes if symptoms persist - most cases improve in 1-2 doses.
   • Record the time of each dose.
   • Stabilize and monitor client.

Vaccine anaphylaxis is not an indication to carry an epinephrine auto-injector (e.g. EpiPen, Allerject, Emerade) long term. However, if an epinephrine auto-injector is available, it can be used in place of a dose of injectable epinephrine.

Epinephrine is the only medication that reduces hospitalization and death, and it should be administered promptly following the onset of anaphylaxis.

What happens after a case of anaphylaxis is identified following vaccination

Anaphylaxis following vaccine administration must be reported to local public health authorities.

Provincial/territorial public health authorities will then remove all personal identifying information and forward reports to the Public Health Agency of Canada as part of the national vaccine surveillance program.

Additional resources

Anaphylaxis management

• Canadian Immunization Guide
• Reporting Adverse Events Following Immunization (AEFI) in Canada
• Cardona et al. World Allergy Organization Journal (2020) 13:100472 http://doi.org/10.1016/j.waojou.2020.100472
• Your local or provincial/territorial public health authority

COVID-19 vaccines

• Vaccines for COVID-19