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Vaccines in Canada and in global markets are monitored continuously. Vaccines go through extensive trials before they can be introduced for people of various age group. Commonly reported side effects of vaccination, such as pain at the site of injection, body chills or feeling tired or feverish, are not considered alarming safety concerns to the health of people. Like all medicines, vaccines may cause side effects that are usually minor and temporary. More serious side effects are extremely rare.

COVID-19 vaccines and side effects

As per Health authorities, vaccines are safe, effective and the best way to save everyone from serious illnesses like COVID-19. Reported side effects to COVID-19 vaccines so far have mostly been mild to moderate and short-lasting. They include fever, fatigue, headache, muscle pain, chills, diarrhoea, and pain at the injection site. The chances of any of these side effects following vaccination differ according to the specific COVID-19 vaccine, though.

Swelling and urticarial rash at the injection site

Swelling and urticarial rash (i.e., hives) at the injection site can occur and may be the first indication of an evolving anaphylaxis. The individual should be kept under observation for considerable time period post vaccination depending upon the vaccines and types in order to ensure that the swelling or hives remain localized. Ice can be applied to the injection site for comfort as per the condition and advice of a healthcare provider. If hives or swelling disappears and there is no evidence of any progression to other parts of the body and there are no other symptoms within the specified observation period, no further observation may be necessary, depending upon the case and condition. An expert opinion is always mandatory in such condition.

Anaphylaxis Reaction

Anaphylaxis is a serious, potentially life-threatening allergic reaction to foreign antigens. It has been found to be associated with some of the vaccines administered. It can be anticipated in every vaccine, per se. Anaphylaxis is preventable in many cases and treatable, though. Symptoms of anaphylaxis often occur within 15-30 minutes of vaccination, though it can sometimes take few hours for symptoms to appear. Vaccinators should be able to distinguish anaphylaxis from fainting and vasovagal syncope, a neurovascular reaction that leads to fainting, as well as anxiety and breath-holding spells, which are all common benign adverse events.

Incidences of anaphylaxis of unknown cause and unrelated to vaccines has been found more during adolescence. Some drugs such as Midazolam is used intramuscularly for relieving anxiety before surgery and anaphylactic shock presenting as severe cardiovascular collapse can occur when it is injected intramuscularly. Although, anaphylaxis during the operative period is not very common, as per the literature, it can be fatal.

Severe or anaphylactic reactions, which are life threatening, are characterized by sudden constriction of bronchiolar muscles, edema of the pharynx and larynx, and severe wheezing and shortness of breath. Immediate medical attention is required to treat anaphylactic reactions. Although anaphylactic shock during the perioperative period is rare, it can be lethal due to severe cardiovascular and respiratory collapse.

Since anaphylactic shock after intramuscular injection can be of slow onset, the administrator must be aware of anaphylactic reaction and be prepared to suitably deal with the condition.

The most important clues for diagnosing anaphylaxis are-

  • clinical presentations such as skin and mucosal involvement

  • respiratory symptoms

  • may be cardiovascular dysfunction

  • information about antigen exposure can provide an indication of the cause of the anaphylaxis

  • Laboratory tests that detect an increase of serum tryptase are the most commonly used diagnostic methods for confirming anaphylaxis.

Pre-vaccination screening

Prevention of anaphylaxis is very important. Pre-vaccination screening includes screening for a history of anaphylaxis and identification of potential risk factors. It should include questions about possible allergy to any component of the scheduled vaccine(s) to identify if there is a contraindication to vaccine administration.

Two types of adverse events are most likely to present acutely:

  • Anxiety-related adverse events following immunization (AEFI) including fainting (vasovagal syncope), hyperventilation and breath-holding

  • Anaphylaxis or other immediate hypersensitivity reactions to vaccine components or the container (e.g., latex).

Risk factors for severe anaphylaxis

Anaphylaxis is not very common complication of immunization. Risk factors for increased severity of anaphylactic events can include:

• very young or old age

• pregnancy

• severe or uncontrolled asthma

• cardiovascular disease

• chronic obstructive pulmonary disease

• systemic mastocytosis

• parallel use of certain medications like beta-blockers.

Each vaccinator who is trained in the treatment of anaphylaxis should have rapid access to an emergency kit with adrenaline and be familiar with its dosage and administration.


IM Injection program and Injection Technique Certificate programs-2 days/3-5 days- training/ certificate program at Springfield College helps prepare you get skills needed for a challenging career in physician’s offices, hospitals or medical clinics. Students learn details and techniques of SC, ID, IM, Depot injections, various vaccines for children and adults, safe and effective Injection techniques, patient communication and preparations in healthcare.

For details of IM Injection training program and Injection Technique Certificate program and the best training-


Bartley’s Square

1- Bartley Bull Parkway, Suite # 19,

(Across Shoppers World Brampton, Above Food Basics)

Brampton, ON, L6W 3T7

Tel: 905-216-1600; 416-456-6689;647-609-3829


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