COVID-19 Update – Dr Theresa Tam

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Dr. Theresa Tam
Dr. Theresa Tam

OTTAWA – COVID-19 Update – The Public Health Agency of Canada (PHAC) continues to monitor COVID-19 epidemiological indicators to quickly detect, understand and communicate emerging issues of concern. The following is the latest summary on national numbers and trends. Next week, I will be providing an update on the latest modelling at a briefing.

Since the start of the pandemic, there have been 1,482,668 cases of COVID-19 and 26,864 deaths reported in Canada. These cumulative numbers tell us about the overall burden of COVID-19 illness to date, while the number of active cases, now at 26,885, and 7-day moving averages indicate current disease activity and severity trends.

Since the last modelling update on July 30th, national daily case counts have continued to increase along the strong resurgence trajectory. The latest national 7-day average of 2,848 new cases reported daily (Aug 20-26) is an increase of 29% over the previous week. After several weeks of rising case counts, national severity trends have begun to increase, primarily involving unvaccinated people. The latest provincial and territorial data show that an average of 917 people with COVID-19 were being treated in Canadian hospitals each day during the most recent 7-day period (Aug 20-26), which is 39% higher than last week. This includes, on average 340 people who were being treated in intensive care units (ICU), 29% more than last week and an average of 9 deaths were reported daily (Aug 20-26).

During this fourth wave of the COVID-19 pandemic in Canada, infections and severe outcomes have several key features:

  • Nationally, the highly contagious Delta Variant of Concern (VOC), accounts for the majority of recently reported cases, is associated with increased severity, and may reduce the effectiveness of vaccines
  • Most reported cases, hospitalisations and deaths are occurring among unvaccinated people
  • Virus spread in areas with low vaccination coverage presents an ongoing risk for emergence of and replacement by new VOCs, including a risk of VOCs with the ability to evade vaccine protection.

Regardless of which SARS-CoV-2 variant is predominating in an area, we know that vaccination, in combination with public health and individual measures, continue to work to reduce disease spread and severe outcomes. In particular, evidence continues to demonstrate that a complete two-dose series of Health-Canada approved COVID-19 vaccines provides substantial protection. Based on the latest data from 11 provinces and territories for the eligible population 12 years or older:

  • from December 14, 2020 to August 7, 2021, 0.03% of fully vaccinated people became infected, with the majority of recent cases and hospitalizations occurring in unvaccinated or partially vaccinated people
  • each week for the period July 11Aug 7, on average:
    • the rate of new COVID-19 cases among unvaccinated individuals was 11 times higher than in fully vaccinated individuals.
    • the rate of COVID-19 hospitalized cases among unvaccinated individuals was 30 times higher than in fully vaccinated individuals.

As of August 26, provinces and territories have administered over 52 million doses of COVID-19 vaccines, with the latest provincial and territorial data indicating that over 83% of people aged 12 years or older have received at least one dose of COVID-19 vaccine and over 75% are now fully vaccinated. Age-specific vaccine coverage data, as of August 21, show that from 60% to 93% of people in the eligible age groupings have received at least one dose and from 73% to 96% are fully vaccinated. As we head into the fall, it is a crucial time to increase vaccination coverage. With the highly transmissible Delta VOC predominating in this wave, we must strive to have as many eligible people as possible fully vaccinated to protect ourselves and others, including those who may not mount a strong immune response or who cannot get vaccinated.

Following Health Canada’s authorization of the Moderna COVID-19 vaccine for adolescents 12 years of age and older, the National Advisory Committee on Immunization (NACI) released updated recommendations on the use of mRNA COVID-19 vaccines in adolescents 12 to 17 years of age. In May 2021, NACI recommended vaccination of adolescents with Pfizer-BioNTech COVID-19 vaccine following regulatory approval and is now including the Moderna COVID-19 vaccine in these adolescent vaccination recommendations. Clinical trial findings suggest the Pfizer-BioNTech and Moderna mRNA COVID-19 vaccines provide very good protection against symptomatic COVID-19 infection and have a favourable benefit versus risk profile in adolescents 12 years of age and older.

In its review of the evidence for this updated guidance, NACI considered the rare cases of myocarditis (inflammation of the heart muscle) and/or pericarditis (inflammation of the tissue surrounding the heart) following immunization with mRNA COVID-19 vaccines, reported both in Canada and internationally. Although, a higher rate of myocarditis and/or pericarditis adverse events were recently reported after administration of the Moderna COVID-19 vaccine compared to the Pfizer-BioNTech vaccine, these events are still considered rare and verification of this potential difference is ongoing. Nevertheless, some provinces and territories may decide to continue using the Pfizer-BioNTech given more experience with this vaccine product in the adolescent age group and the possibility of a lower rate of myocarditis and/or pericarditis. Safety of vaccines remains a top priority and Canada continues to closely monitor the safety and effectiveness of all COVID-19 vaccines.

Given the importance of vaccinating adolescents before the fall and the return to school, NACI’s updated recommendations will help provinces and territories to continue to rollout COVID-19 vaccination programs to better protect the health and wellbeing of adolescents, their families and communities. In addition, NACI is actively reviewing emerging evidence on the potential benefit of an additional dose in certain populations, including those who are immunocompromised and seniors in congregate living.

For additional information regarding vaccination in your area, reach out to your local public health authorities, healthcare provider, or other trusted and credible sources, such as Canada.ca and Immunize.ca. Canada.ca provides a broad range of COVID-19 information and resources to help Canadians understand the benefits of being vaccinated against COVID-19 and find guidance on life after vaccination.

While COVID-19 is still circulating in Canada and internationally, core public health practices remain crucial: stay home/self-isolate if you have symptoms; be aware of risks associated with different settings; follow local public health advice and maintain individual protective practices. In particular, physical distancing and properly wearing a well-fitted and well-constructed face mask provide additional layers of protection that further reduce your risk in all settings. Canadians are advised to continue avoiding non-essential travel outside of Canada; if you must travel, be aware of the requirements for visiting other countries and for returning to Canada.

Canadians can also go the extra mile by sharing credible information on COVID-19 risks and prevention practices and measures to reduce COVID-19 in communities. Read my backgrounder to access more COVID-19 Information and Resources on ways to reduce the risks and protect yourself and others, including information on COVID-19 vaccination.

SOURCE Public Health Agency of Canada