COVID-19 variants of concern

Find information on recently identified variant strains of the COVID-19 virus.

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Variants are viruses that have changed or mutated from the original viral strain while reproducing inside an infected person’s cells. Variants can spread to others and may continue changing as they move from person to person. It is normal for viruses to evolve and change over time. 

Most mutations do not cause more severe illness, but some may change how a virus behaves. These changed viruses are considered variants of concern and may spread more easily, cause more severe illness, require different treatments, affect the reliability of diagnostic tests, or have reduced vaccine effectiveness.

COVID-19 variants of concern first identified in other countries may spread and be detected in Alberta and around the world. Alberta is monitoring for variants spreading in our province.

See variant case data in Alberta

Reduce the risk

Variants of concern can be prevented the same way as the original virus:

Variants of concern in Alberta

To date, 5 variants of concern have been identified in Alberta. The B.1.1.529 (Omicron) variant and its descendants are the dominant strain in Alberta.

Anyone who has been infected with a variant strain will test positive for COVID-19. Positive tests are screened again for all variants to determine the exact strain.

  • Alpha

    First identified in the United Kingdom, research has shown this variant spreads more easily and can cause more severe illness in comparison to the original COVID-19 strain.

  • Beta

    First identified in South Africa, research has shown this variant spreads more easily than the original COVID-19 strain and may be capable of re-infecting people who have previously tested positive for COVID-19.

  • Gamma

    First identified in Brazil, research has shown this variant spreads more easily than the original COVID-19 strain and is capable of re-infecting people who have previously tested positive for COVID-19.

  • Delta

    First identified in India, research has shown this variant spreads more easily than the Alpha variant and causes an increased risk of hospitalization and re-infection of people who have previously tested positive for COVID-19.

  • Omicron

    First identified in South Africa, this has been the most common variant in Alberta and worldwide throughout 2022. It is the dominant strain globally because it spreads easily. Omicron continues to acquire new mutations as it spreads.

    These mutations are not different enough from Omicron to be considered new variants. Instead, they are referred to as subvariants. Some examples of Omicron subvariants are BA.2, BA.4, and BA.5. They are closely related to the original Omicron strain, but have slight differences. Evidence suggests Omicron and its subvariants are more infectious so people who have been previously infected with COVID-19 can be reinfected more easily.

    As Omicron spread globally, we learned that the risk of severe disease is reduced compared to the Delta variant. However, the increased transmission means many more people have become infected, which has caused significant impact on individuals and health systems. As with all COVID-19 variants, the risk of disease severity may depend on other factors, such as age and chronic disease.

What we know

Knowledge and understanding of the COVID-19 variants is evolving rapidly. Scientists and public health officials around the world are studying variant strains and how the current vaccines may help protect against them.

Current evidence suggests:

  • most are more contagious and spread more easily than the original strain
  • some cause more severe illness, which could result in more hospitalizations and deaths (such as Delta)
  • all have the same symptoms as the original virus, including cough, fever, shortness of breath, runny nose, and sore throat (see the full list of symptoms)

Learn more about COVID-19 variants.

Vaccine effectiveness and protection

The Pfizer, Moderna and Novavax vaccines currently available in Alberta offer protection against infection and severe outcomes with variants. However, the level of protection may vary depending on the variant and the number of doses received.

Case study: How one case turned into many

One Albertan returned from travel with COVID-19. Instead of quarantining alone for 14 days following return from travel outside Canada, the infected traveller socialized with a friend during quarantine.

This triggered a chain of COVID-19 infections that spread far beyond that first individual. This is a real example, discovered through the contact tracing process conducted by Public Health.

This infographic shows the spread of a COVID-19 variant of concern from one person to 42 from January 1 to February 5.