Tracking variants of the novel coronavirus in Canada
As COVID-19 continues to spread, several more contagious variants of the novel coronavirus are spreading across Canada.
There are currently four variants of concern (VOCs) that have been identified and are being tracked by provincial health authorities and the Public Health Agency of Canada: B.1.1.7, B.1.351, P.1. and B.1.617.
In addition to these four variants, some provinces have identified cases of other variants of interest not currently reflected in our data. Updates may be made if the Public Health Agency of Canada designates new variants of concern.
CTVNews.ca’s variant tracker is keeping a daily count of these VOCs, with a provincial breakdown by variant that you can see in the above tables.
Additionally, CTVNews.ca is now tracking ‘screened’ COVID-19 cases, which have been identified as mutations but are yet to be confirmed which variant they belong to. The provinces that have started to identify these screened cases include Ontario, Quebec, Manitoba and Saskatchewan.
- These screened cases appear in our bar chart above in beige. B.1.1.7 variants are represented in dark brown, B.1.351 in orange, and P.1 in red
By adding this screened data, we hope to provide a more accurate estimate of how many VOCs are circulating in Canada.
Notably, as of Apr. 8, 2021, Ontario changed its methodology for confirming B.1.1.7 variants. Previously, genome sequencing was required for a sample to be confirmed as the B.1.1.7 variant. Going forward, Public Health Ontario (PHO) will use results from initial screening tests to classify B.1.1.7 variants without waiting for the time-consuming sequencing process.
According to PHO media relations, “given the accuracy of the [polymerase chain reaction] variant test and what we now know about the prevalence of B.1.1.7 in Ontario, genome sequencing is no longer required to confirm that a sample positive for the N501Y mutation but negative for the E484K mutation is likely a B.1.1.7 variant.”
Outside of Ontario, Quebec, Manitoba and Saskatchewan, our tracker shows only lab-confirmed cases of variants of concern, meaning those that have undergone genetic sequencing. Read more about the testing and publishing process here.
- Can't see the tracker? Click here.
The virus has spikes on its surface that helps it attach onto human cells. Scientists say that these new variants of the virus have changes in their spikes, which can cause them to interact with the human body differently than the original virus.
B.1.1.7 first emerged in the U.K. in September 2020. Doctors say that this variant spreads faster than others, and could be transmitted in less time than the original strain.
The B.1.1.7 variant is the most prominent in Canada, with hundreds of cases having been identified. Ontario has seen the most number of cases, where an outbreak involving this variant at a long-term care home has resulted in all residents but one contracting the virus and more than 100 positive cases amongst staff.
The B.1.351 variant was first discovered in South Africa in December 2020. Scientists say that this variant is more efficient than others in targeting healthy cells.
P.1 was first identified in December 2020 when this variant caused one of the deadliest outbreaks in Manaus, Brazil. According to the U.S. Centers for Disease Control and Prevention, contracting this variant could affect the ability of antibodies developed from previous infections and vaccinations. Canada reported its first case of this variant on Feb. 7.
Public Health Ontario issued in their epidemiologic summaries that variant tracking data may change as they continue to analyze cases:
Caution should be taken when interpreting [variants of concern] data due to the nature of the screening and confirmation process, including delays between specimen collection and whole genome sequencing.
Data corrections or updates can result in case records being removed and/or updated and may result in totals different from past publicly reported case counts.
Stephanie Liu contributed to this project
Data is collected from official provincial sources, including live press conferences. Not all provinces currently publish updates online.
Ontario: Daily epidemiologic summaries
British Columbia: Website
New Brunswick: Website
Nova Scotia: Website
Prince Edward Island: Website
Newfoundland and Labrador: Website