conflictanalyticslab

By: Meena Durrani

The following post provides a brief overview of some of the highlights on the current state of vaccine side effects in Canada.

This information and more details can be found at the Government of Canada Website.

Experiencing temporary side effects following a COVID-19 vaccine is considered normal. This is the body’s natural response in building immunity against the disease and is called the inflammatory response or reaction.[1] In Canada, even after vaccines are approved safety monitoring by Public Health Agency of Canada (PHAC), Health Canada, and provincial and territorial health authorities remains ongoing.[2]

According to the Government of Canada’s website, a total of 57,265,088 vaccine doses have been administered in Canada as of October 15, 2021. Adverse events (side effects) have been reported by 19,984people. That’s about 3 people out of every 10,000 people vaccinated who have reported 1 or more adverse events.[3]

Of the 19,984 reports, 5,161 were considered serious but overall, the rate of serious reports has remained low. [4] It is important to note that all reports of adverse events following immunization received by Health Canada and PHAC are included in this report, regardless of whether they have been linked to the vaccines for the purpose of further research.

The following are the most frequently reported adverse events as reported on the Government of Canada website:[5]

  • Paraesthesia (tingling or prickling)
  • Vaccination site pain
  • Headache
  • pruritus (itching)
  • Dyspnoea (laboured breathing)
  • Fatigue
  • Urticaria (hives)

The least frequent reports include:

  • Vaccination site rash
  • Lip swelling
  • Anaphylaxis
  • Flushing
  • Dysphonia (hoarse voice)
  • Dermatitis allergic

Adverse Events of Special Interest

Adverse events of special interest (AESI) are pre-specified medically significant events that have the potential to be causally associated with a vaccine product. Again, it is important to note that although these adverse events may occur after being immunized with a COVID-19 vaccine in Canada, they are rare and may not necessarily be related to the vaccine. [6] AESI are reported under the following categories with the subtotal of number of events:[7]

  • Auto-immune diseases: 150
  • Cardiovascular system: 1094
  • Circulatory system: 932
  • Hepato-gastrointestinal and renal system: 65
  • Nerves and central nervous system: 757
  • Other systems: 559
  • Pregnancy outcomes: 43
  • Respiratory system: 3
  • Skin and mucous membrane, bone, and joints system: 40

Adverse event following immunization reports by vaccine name:

Pfizer-BioNTech Comirnaty

Total Reports: 11, 300

Serious Reports: 3, 457

Moderna Spikevax

Total: 5,963

Serious Reports:  912


AstraZeneca Vaxzevria/COVISHIELD

Total: 2, 563

Serious: 644

Adverse Events by age and gender/sex:

  • The rate of reported adverse events was highest among the 40 to 49 year age group followed by those in the 50 to 59 year age group (41.9 reports per 100,000 doses administered).
  • Brown, a microbiologist from the University of Ottawa, says age is perhaps the biggest determining factor, noting older people, who tend to have less robust immune systems report fewer reactions[8].
  • Overall, the majority of adverse event reports were from females (74.8%) and the rate of reports for females was 50.1 reports per 100,000 doses administered, compared to 17.9 per 100,000 doses administered for males.

It is unknown whether the difference in gender reports could be accounted for by a biological difference or health-seeking behaviour in reporting adverse events between male and female.

Most Reported Adverse Events of Special Interest

Up to and including October 15, 2021, the most reported AESI were myocarditis/pericarditis and Bell’s Palsy.

  1. Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the lining around the heart. Up to and including October 15, 2021, there were 956 reports of myocarditis/pericarditis that were considered serious. The reporting rate of myocarditis following vaccination with Moderna Spikevax is approximately double that of Pfizer BioNtech Comirnaty, for all ages and sexes combined. On September 29, 2021, out of an abundance of caution, Ontario issued a preferential recommendation for the use of Pfizer-BioNTech Comirnaty vaccine for individuals 18-24 years of age, and the continued use of Pfizer-BioNTech for individuals 12-17 years of age, based on an analysis of data from Ontario’s AEFI surveillance system. [9]
  • Bell’s palsy is an unexplained episode of facial muscle weakness or paralysis. It begins suddenly and worsens over 48 hours. This condition results from damage to the facial nerve. Pain and discomfort usually occur on one side of the face or head. Bell’s palsy can strike anyone at any age.[10] Up to October 15, 2021 – there have been 574 number of Bell’s Palsy reported events.
  • Rare Side Effects:

Myocarditis: Inflammation of the heart muscle

Pericarditis: Inflammation of the lining around the heart

Bell’s Palsy: Facial paralysis

Blood clots with low platelets:

Blood clots with low levels of blood platelets that occur after vaccination with viral vector vaccines (AstraZeneca Vaxzevria/COVISHIELD) are rare but serious

Capillary Leak Syndrome:

A small number of reports of this rare condition have been reported following vaccination with the AstraZeneca Vaxzevria/COVISHIELD vaccine. Some of the reports reviewed were in individuals who have had this condition previously.

Guillain-Barre Syndrome (GBS):

A number of reports of people developing this rare disorder after receiving the COVID-19 viral vector vaccine. This number is higher among individuals that received the AstraZeneca Vaxzevria/COVISHIELD vaccine compared to what’s expected in the general population.

Source: Weekly Report on side effects following immunization. Canada.ca. Retrieved October 27, 2021, from https://health-infobase.canada.ca/covid-19/vaccine-safety/#a6

The ongoing safety signals which are actively being monitored include:

  1. Thrombocytopenia syndrome following vaccination with AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccine. 
  • Guillain-Barré Syndrome (GBS) in Canada following AstraZeneca Vaxzevria/COVISHIELD COVID-19 vaccination.
  • Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining around the heart) following vaccination with COVID-19 mRNA vaccines. 

For more information, see: https://health-infobase.canada.ca/covid-19/vaccine-safety/#a6

Disclaimer: The information provided in this response is for general informational purposes only and is not intended to be legal advice. The content provided does not create a legal client relationship, and nothing in this response should be considered as a substitute for professional legal advice. The information is based on general principles of law and may not reflect the most current legal developments or interpretations in your jurisdiction. Laws and regulations vary by jurisdiction, and the application and impact of laws can vary widely based on the specific facts and circumstances involved. You should consult with a qualified legal professional for advice regarding your specific situation.

[1] Canada, P. H. A. of C. (2021, October 22). Covid-19 Vaccine Safety: Weekly Report on side effects following immunization. Canada.ca. Retrieved October 27, 2021, from https://health-infobase.canada.ca/covid-19/vaccine-safety/#a6.

[2] See Footnote 1

[3] See Footnote 1

[4] See Footnote 1

[5] See Footnote 1

[6] See Footnote 1

[7] See Footnote 1

[8] Global News: The Canadian Press Staff. (2021, April 12). Mild, temporary vaccine side effects? that’s a sign they’re working, experts say – national. Mild, temporary vaccine side effects? That’s a sign they’re working, experts say. Retrieved October 27, 2021, from https://globalnews.ca/news/7696621/covid-vaccine-canada-side-effects-explained/.

[9] Ontario Recommends the use of Pfizer-BioNTech COVID-19 Vaccine for Individuals Aged 18-24 Years Old. Government of Ontario. (2021, September 29). Retrieved October 27, 2021, from https://news.ontario.ca/en/statement/1000907/ontario-recommends-the-use-of-pfizerbiontech-covid-19-vaccine-for-individuals-aged-18-24-years-old.

[10] The John Hopkins University. (2021). Bell’s Palsy. Johns Hopkins Medicine. Retrieved October 27, 2021, from https://www.hopkinsmedicine.org/health/conditions-and-diseases/bells-palsy#:~:text=Bell’s%20palsy%20is%20an%20unexplained,strike%20anyone%20at%20any%20age.

Disclaimer: This article provides information of a general nature only. It does not provide legal advice nor can it or should it be relied upon. All scenarios are specific to their facts and will differ from the situations in the articles. If you have specific legal questions you should consult a lawyer.