The U.K. variant: questions and answers

Over the past month, Nova Scotia reported six cases of COVID-19 that were identified as variants. Five out of six were confirmed to be the B.1.1.7 variant first identified in the U.K. with the sixth being the B.1.351 variant first identified in South Africa.

So far, the province has not seen confirmed community spread in relation to these variants. But Dr. Robert Strang, Nova Scotia's chief medical officer of health, said at Friday's live briefing that it wasn't out of the question. In fact, it's one of the concerns fueling a return to restrictions in the greater Halifax area starting Saturday.

"If you let a variant start to spread, ... it's very hard to control," he said.

In neighbouring Newfoundland and Labrador, the B.1.1.7 variant is behind the spike in COVID-19 cases that caused the province to return to its strictest level of public health restrictions. Researchers across the world are continuously trying to understand what this variant could mean for our response to the pandemic. Here is some of what they know:

What is a variant? Are all variants concerning?

When a virus infects a person, it hijacks the person's cells and uses them to replicate its genetic material. Essentially, the cell becomes a factory that pumps out large amounts of virus offspring, before getting destroyed as the offspring exit to infect other cells.

During this process, errors could occur making the offspring's genetic material slightly different from the parent. These errors are called mutations and viruses with these mutations are called variants.

All viruses mutate. It's completely normal. Since the beginning of the pandemic, SARS-COV-2, the virus causing COVID-19, has been mutating continuously as it spreads from one person to the other across the world. Previous variants weren't concerning for scientists because the mutations weren't significant.

But sometimes, the genetic material is different enough to change the behaviour of the virus compared to its predecessors. For example, it may change how transmissible a virus is, what symptoms it causes, or give it an added ability to evade a vaccine or a drug. In some cases, the change makes it more difficult for the virus to replicate, causing this variant to disappear. But in other cases, such as the B.1.1.7 variant, the changes are advantageous to the virus and that's when it could become a concern.

Where did the B.1.1.7 variant come from?

It's still not clear how exactly the variant came to exist. Some researchers hypothesize that the virus gained more mutations after spending a long time in a patient's body. For example, if the virus infects someone with a week immune system, such as an immunocompromised person, it can thrive in their bodies for months. The more time it has to replicate, the more mutations the virus's genetic material could acquire. This could explain how the B.1.1.7 variant acquired multiple mutations in a relatively short period of time.

Is the B.1.1.7 variant more contagious?

It appears to be. The variant has spread quickly, suggesting that it could be more easily transmitted among people. This could be a result of a mutation in the virus's spike protein, a bump on the surface of the virus that allows it to latch onto host cells. The mutation is believed to make it easier for the virus to infect people. Other research suggests that people with this variant produce more infectious virus compared to previous variants. What that means is that when a person with the variant coughs or speaks, they expel more virus in their droplets.

The B.1.1.7 variant's potential ability to spread quickly is a great concern for scientists. What we've seen in Newfoundland and Labrador is an example of how difficult it could be to control the variant. At a live briefing Wednesday, Dr. Strang said that masks, physical distancing, and all the other measures we have in place will help limit the spread of the virus, regardless of the variant.

Does it cause more severe disease?

There's no clear evidence that the B.1.1.7 strain causes more severe symptoms or that it's more deadly.

At Wednesday's COVID-19 briefing, Dr. Strang said cases in Newfoundland and Labrador, where the B.1.1.7 variant is believed to have caused the recent outbreak, are mostly very mild, often asymptomatic.

Are vaccines effective against the B.1.1.7 variant?

It's not very clear how protective all vaccines are against the coronavirus variants. The three vaccines approved in Canada appear to provide protection. Studies by Pfizer-biontech and Moderna suggest that their vaccines are effective against the B.1.1.7 variant. The researchers who developed the Oxford-astrazeneca vaccine, which was approved by Health Canada Friday, have found that the vaccine also works.

Dr. Strang said Friday that there's nothing to suggest that the vaccines aren't effective.