Variants of Concern
All viruses mutate. As viruses spread, they produce mutations, which happens because as a virus replicates, its genes may undergo random "copying mistakes.” These errors in replication can lead to changes in the virus’s proteins or antigens. The mutation process is inevitable, and epidemiologists predicted that SARS-CoV-2, the virus that causes COVID-19, would also follow this pattern. We call the mutated strains of virus "variants” and scientists and public health officials have been tracking them since the outset of the pandemic. Many of the mutations that have occurred to SARS-CoV-2 are minor, and don’t have much impact on the spread of the virus or severity of illness caused -- in fact, some changes in the virus’s genes may serve to weaken it. However, occasionally a mutation actually helps the virus copy itself more efficiently or improves the ability of the virus to invade cells. Epidemiologists label some of these mutations "variants of concern.” Due to the global reach of the pandemic and the fact that millions of people have been infected, it was only a matter of time before some variants of concern (or VOCs) arose.
A variant becomes a "variant of concern” when its changes affect:
- Transmissibility, or the spread of the virus
- Virulence or the severity of the disease caused
- Vaccine effectiveness, or how well the current vaccines will work against the variant
- Diagnostic testing, or whether or not the variant can be picked up by current testing methods.
What Scientists Are Monitoring
The variants of concern that have been identified in Canada are:
- B.1.1.7 variant, first identified the UK, sometimes known as the "British variant” or the "Kent variant.”
- B.1.351 variant first identified in South Africa
- P.1 variant, first identified in Brazil
- B.1.525 variant, first identified in Nigeria
Some VOCs are mainly a source of concern due to the fact that the changes to the virus involve the spike protein. This has two different ramifications. The spike protein is the aspect of the virus that allows it to attach to and enter our cells. The VOCs display a change in the spike protein that leads to increased transmissibility, meaning that the variants spread more easily. Some estimate that B.1.1.7, the British variant, spreads more than 50% more efficiently than the original COVID-19 virus. Obviously, faster spread is a problem for already overburdened medical systems.
Another potential problem is that the current vaccines target the spike protein. If the spike protein mutates to the point where the vaccine doesn’t recognize it, it could render vaccination powerless. However, vaccine makers think that current vaccines produce a broad enough immune response that they will remain effective against variants of concern. Vaccine manufacturers are also confident that they can produce boosters that will be effective against VOCs. However, developing new and effective vaccines takes time, and time allows further mutations of the virus to happen.
While VOCs are obviously unsettling, the best thing we can do is to try to stop the spread of the virus. The same techniques work on every variant of the virus: wear effective masks or face coverings, stay two metres away from people from outside your household, stay home except for essential reasons, and wash your hands frequently. Stay vigilant, and stay safe!