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COVID-19 Variants

Viruses naturally change over time and these changes can lead to new versions or variants.

Last updated: September 22, 2023

What are variants?

It is normal for viruses to change over time. As viruses multiply, they have a chance to change. These changes happen at the genetic level and are called mutations. 

Many genetic changes don't have a big impact but some lead to new versions of the virus that behave differently. These versions may be referred to as new variants or lineages or sublineages.  

New variants can spread in communities at different rates, cause more mild or more serious illness, or impact how well current treatments or vaccines work against the virus.

New COVID-19 variants will continue to occur

SARS-CoV-2, the virus that causes COVID-19, has changed or mutated many times. There have been several new variants that are different from the original SARS-CoV-2 virus, such as Alpha, Beta, Gamma, Delta, and Omicron variants.

As SARS-CoV-2 continues to spread, there will be more variants. New variants are more likely to happen when COVID-19 is spreading quickly in a population because more copies of the virus are being made and mutations are more likely to happen.

New variants are monitored for how easily they spread and whether they cause severe disease. The Omicron variants spread more easily between people because of mutations in the part of the virus known as the spike protein.  

Tools to prevent COVID-19 infection and reinfection

People who have had COVID-19 can get infected again with new variants. This is called reinfection.

There are a number of actions you can take to help prevent COVID-19 and serious illness:

  • Stay up to date on your vaccinations
  • Stay home when sick and stay away from those who are at higher risk of more serious illness
  • Wear a mask in places where it is required, if you are sick and cannot stay away from others, and as a personal choice
  • Clean your hands regularly
  • Open windows or have good ventilation

Vaccination and COVID-19 variants

People who are vaccinated are less likely to end up in the hospital from SARS-CoV-2 infection than people who are not vaccinated. This is why it is important to stay up to date on your immunizations.

Vaccines are updated regularly to help protect against the latest variants. When a new variant starts spreading, scientists monitor how well the vaccines work to prevent serious illness from it. To date, the vaccines have helped prevent serious illness and hospitalization even when new variants start spreading.

Monitoring for COVID-19 variants in B.C.

B.C. monitors for variants by studying the genetic makeup of positive COVID-19 PCR test samples and wastewater. This helps us understand which variants are circulating and how that changes over time. We also look at this type of data from around the world to understand if new variants could come into B.C. 

For information on the variants currently circulating in B.C., visit the Genomic Surveillance report.

All variants currently causing infection in B.C. are types of the Omicron variant.

Classification of variants, lineages and sublineages

Scientists use classification systems to describe variations in the SARS-CoV-2 virus:


Some examples of Omicron lineages and sublineages include:

  • BA.2.86 
  • EG.5 
  • BA.1
  • BA.2
  • BA.2.75
  • BA.4
  • BA.5
  • BA.1
  • BQ.1.1
  • XBB
  • XBB.1.5

Other variants that previously circulated in B.C.:
  • Alpha
  • Beta 
  • Gamma
  • Delta

Common terms and definitions

As viruses multiply, errors can happen in their genetic make-up. These errors are called mutations.


A group of viruses that are different from the original virus, but all share the difference.


A subgroup of the viruses within the lineage group that have a smaller set of differences in common.


Some variants can merge to form a hybrid or recombinant version. Recombinant viruses are monitored in the same way that new variants are monitored, to determine how easily they spread, if vaccines work against them and other properties. 

These terms are used to describe some variants. Health organizations develop definitions based on the impact a new variant is expected to have on a population, whether it is meaningfully different from other lineages, and how much is known about it.

Learn about the Public Health Agency of Canada definitions

SOURCE: COVID-19 Variants ( )
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