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 which 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, VoC classifications can include sublineages which share genetic changes.
BC aligns with the Public Health Agency of Canada (PHAC) to determine which variants are classified as VoCs. Currently, the VoCs include:
Alpha (B.1.1.7) the variant first reported in the UK spreads more easily and can cause more severe illness. Alpha also includes the Q.* sublineages.
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.
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.
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 the AY.* sublineages.
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 VOIs have been given WHO names and others remain unnamed. In some cases, VOI are downgraded when researchers no longer consider them a concern, although agencies continue to monitor for them.
The VOIs of interest to B.C. scientists include (in alphabetical order):
Eta (B.1.525) which was first detected in Nigeria in late 2020.
Epsilon (B.1.427 and B.1.429) variants first reported in California, USA. Both spread more easily, and some current treatments and vaccines may not work as well on cases of this variant. In July 2021, Epsilon was downgraded to alert status and is no longer a variant of interest.
Iota (B.1.526 and B.1.526.1), variants first detected in New York in late 2020.
Kappa (B.1.617.1), a sublineage of B.1.617, the variant first detected in India.
Lambda (C.37), first detected in Peru.
Theta (P.3), which may have similar properties to Gamma and Beta. In July 2021, Theta was downgraded to alert status and is no longer a variant of interest.
Zeta (P.2), a variant first detected in Brazil in early 2020. Some treatments and vaccines may not work as well on this variant. In July 2021, Zeta was downgraded to alert status and is no longer a variant of interest
- Mu includes B.1.621 and C.1.2. Mu is a relatively recent variant and is being closely monitored.
B.1.618, a variant first detected in India that is also referred to as the “triple mutant”.
A current list of all the variants that have been detected in B.C. is available in Table 2 in the report on the
variants section on the BC COVID-19 data page
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. Some variants have the same genetic changes, even though they were first detected in different countries. Other variants, such as Delta, have at least two sets of changes that can impact how the virus behaves in the body.