It is normal for viruses to change over time. Some viruses, like influenza, change often while other viruses hardly change at all over many years. Most genetic changes in a virus don't have much impact but some lead to new variants that can act differently in ways that are important to public health.
When genetic changes lead to a variant that can spread more easily, cause more serious illness, or impact current treatments or vaccine effectiveness, it is called a variant of concern (VoC). In some cases, variant of concern classifications can include lineages and sublineages that share genetic changes.
Variants of viruses naturally merge to form a hybrid or recombinant versions. Scientists have identified this process in the COVID-19 virus. A Delta-Omicron recombinant has been detected recently in the USA, UK, Australia, and parts of Europe but the number of cases of this version remains low. The sequencing technology used in B.C. is capable of detecting recombinant variants of COVID-19.
BC aligns with the Public Health Agency of Canada (PHAC) to determine which variants are classified as variants of concern. Currently, the variants of concern include:
Omicron (B.1.1.529), was first detected in South Africa on November 9, 2021. Omicron has mutations in the spike region, which affects how it spreads and how it responds to treatments and vaccinations. vaccinations.
- The Omicron variants includes many lineages such as BA.1 and BA,2*, and sublineages (BA.2.12, BA.1.1* etc.).
Figure 1 in the weekly data report lists the current Omicron sublineages that have been detected in the province.
Delta (B.1.617.2) is a sublineage of B.1.617, which was first detected in India. Delta spreads more easily and may lead to more severe disease, particularly for unvaccinated people. Delta includes B.1.617.2 and many AY.* sublineages.
Gamma (P.1) the variant first reported in Japan but later identified as originating in Brazil, which may be able to re-infect people who have had COVID-19. Gamma includes two sublineages P.1.1 and P.1.2. Some current treatments may not work as well on cases of this variant.
Beta (B.1.351) the variant first reported in South Africa, spreads more easily than older strains and has numerous sublineages. Some current treatments and vaccines may not work as well on cases of this variant and its sublineages, yet this VoC did not become established globally.
Alpha (B.1.1.7) the variant first reported in the UK spreads more easily and can cause more severe illness than previous versions. Alpha also includes the Q.* sublineages.
Viruses naturally evolve over time, and some variants can merge to form a hybrid or recombinant version. Scientists have identified COVID-19 recombinants, such as the Delta-Omicron recombinant detected in the USA, UK, Australia, and parts of Europe.
So far, the number of COVID-19 cases due to recombinants variants remains low. The sequencing technology used in B.C. detects COVID-19 recombinants and these are reported in the weekly data report by using an “X”.
Recombinant viruses are monitored in the same way that new variants are monitored, to determine their transmissibility, vaccine escape and other properties.
The BCCDC is also actively monitoring for new variants of interest (VOI) as they emerge around the world and assessing whether these variants have been identified in B.C.
Some variants of interest have been given WHO names and others remain unnamed. In some cases, variants of interest are downgraded when the scientific community no longer considers them a concern, although agencies continue to monitor for them.
Experts and scientists are studying the new COVID-19 variants to better understand their impact and if they change the course of COVID-19 illness. Early studies suggest that current vaccines will continue to provide good protection against severe disease.