COVID-19 variants of concern
On this page
About the variants
- The virus that causes COVID-19, like all viruses, is constantly changing. When there have been several significant mutations to the virus then it's called a variant.
- Globally, there are various COVID-19 variants that exist and some may become a concern to public health. A variant is of concern when it affects:
- disease spread
- disease severity
- tests used to detect the virus
- vaccines and treatment effectiveness
- Most notably the following have been detected in Canada and are considered variants of concern:
- Alpha (B.1.1.7)
- Beta (B.1.351)
- Gamma (P.1)
- Delta (B.1.617)
- Omicron (B.1.1.529)
- Evidence demonstrates that Alpha and Delta variants are at least 50% more transmissible than the original version of the virus identified at the beginning of the pandemic.
- The Gamma, Beta and Delta variants each have mutations that may have an impact on vaccine effectiveness.
- Early evidence suggests that Omicron is likely more transmissible than other variants of concern identified to date. Studies are underway to determine how much is due to:
- Omicron's natural ability to spread
- a reduction in immune protection following vaccination or previous infection
- Variants were initially imported via travel from outside the country. There is an increase in community spread of these variants of concern
- The Government of Canada continues to work with the provinces, territories and Indigenous partners to track and respond to these variants of concern
- Indigenous Services Canada (ISC) continues to:
- review new research and information about the COVID-19 variants as they become available
- provide updates at various leadership and collaborative tables with partners
- New variants will continue to appear. Everyone must continue to implement all available public health measures to limit the spread of COVID-19, including:
- vaccination
- hand hygiene
- physical distancing,
- stay home when ill
- wear an appropriate mask
Contact tracing and testing
- The COVID-19 point of care tests cannot detect if a case of COVID-19 is caused by the original COVID-19 strain or the variants of concern. In order to test for variants, positive samples undergo sophisticated testing in provincial and national laboratories
- If an individual's sample is suspected or confirmed as a variant of concern, local public health authorities will contact that person about the next steps to be taken
- Local public health organizations and Indigenous community leadership will continue to work together to follow provincial or territorial guidelines for:
- contact tracing
- testing
- isolation
- other public health measures
Interim public health measures
- This interim public health guidance is intended to protect individuals living in the same household with someone who has COVID-19 or who meet any of the criteria below:
- have returned from outside of Canada in the past 14 days
- have been in close contact (with or without PPE) with a confirmed case of COVID-19 within the past 14 days
- show symptoms
- have tested positive for COVID-19 in the past 14 days
- It is recommended that people with presumptive or confirmed COVID-19 variants of concern:
- isolate in alternative isolation accommodations when possible
- when a family member in the household is directly caring for a COVID-19 positive member, they are to wear a well-fitted non fit tested respirator. All other family members are to wear a medical mask when in the same room as the individual with COVID-19, attempting to maintain 2 metres of physical distancing
- eat and sleep in a separate room from other household members so that masks can be removed during these activities
- To find out more about medical masks, visit:
- This is an important step to stop the variants of concern from spreading to other people in the household as well as the community. Individuals should follow their provincial or territorial advice on alternative isolation accommodations and isolation protocols
- Additional studies are needed to determine the optimal length of isolation for close contacts and those that have been vaccinated. This will be influenced by the circumstances of the exposure. Individuals should follow their provincial or territorial health authority's guidance for isolation or quarantine after COVID-19 exposure, including exposure to variants of concern
- While vaccines are having a significant impact on reducing the burden of COVID-19 associated hospitalizations, the virus continues to circulate. People who are fully vaccinated can still be infected and transmit the COVID-19 virus, including the Omicron variant, although this is more likely to occur among unvaccinated or partially vaccinated individuals
- Even if you have received a complete series of COVID-19 vaccines, it is important to continue to follow local public health guidelines and continue practicing all public health measures including:
- washing your hands often
- staying home when you're sick
- maintaining physical distancing
- wearing a face mask
- If you don't have access to medical masks, here are the public health guidelines and additional information on the use of non-medical masks: