International research review

At the beginning of the pandemic, SARS-CoV-2 infections in children and adolescents in Canada were rare and generally very mild compared to adults. However, with the emergence of Omicron in December 2021 the weekly number of new COVID-19 cases in those under the age of 18 spiked to 55,956, accounting for 19% of the total number of COVID-19 cases in Canada (1). This change has been attributed to the increased transmissibility of Omicron and low vaccine uptake among children.

Social and economic inequities play a critical role in understanding why numerous diseases disproportionately burden certain communities in Canada and around the world. COVID-19 has not been an exception.

The COVID-19 pandemic has exposed vulnerabilities faced by many populations, including the Two-Spirit, lesbian, gay, bisexual, transgender, queer, non-binary, and sexual minority (2SLGBTQ+) communities.

People who are at a higher risk of severe COVID-19 include individuals with poor immune function due to underlying medical conditions or due to immune-suppressant medications. In these populations, risk mitigation measures against COVID-19 are particularly important.

Older Canadians have shouldered a disproportionately heavy burden of severe illness and death during the COVID-19 pandemic. As of September 16th, 2022, people over age 70 have accounted for 82% of all deaths, 35% of all intensive care admissions, and 50% of all hospital admissions due to SARS-CoV-2 infection in Canada.

Pregnant people are at an increased risk of adverse effects from SARS-CoV-2 infection (the infection that causes COVID-19 disease) and are more likely to be admitted to an intensive care unit compared to non-pregnant individuals (1-4). Overall, people with COVID-19 who are pregnant are 2.65 times more likely to require hospitalization and 5.46 times more likely to be admitted to ICU than non-pregnant individuals with COVID-19 (4). COVID-19 has also been associated with increased risks of preeclampsia, preterm birth, and other adverse pregnancy outcomes (5). Thus, vaccination is an important tool for ensuring a healthy pregnancy.

As the COVID-19 pandemic evolves and new variants of SARS-CoV-2 emerge, incidents of breakthrough infections among vaccinated individuals and reinfections among previously infected individuals have risen worldwide.

As of April 26, 2022, more than 3.7 million SARS-CoV-2 infections and approximately 38,847 COVID-19-related deaths have been reported in Canada. The National Advisory Committee on Immunization (NACI) recommends COVID-19 vaccinations for all Canadians over the age of 5, including those who have been previously infected.

Earlier SARS-CoV-2 variants of concern such as Alpha, Beta, and Gamma did not lead to significant upticks in pediatric hospitalizations. However, the rise of the highly transmissible Delta and Omicron variants, coupled with the loosening of public health restrictions and the vaccination of adolescents and adults, have since altered that reality.

While most people infected with SARS-CoV-2 recover within 2-4 weeks with limited complications, some adults and children continue to face persistent symptoms long after the initial infection.