Based on the evidence so far, researchers believe the B.1.1.7 lineage that was first discovered in the United Kingdom is up to 70 per cent more contagious than other variants. It is not yet clear, however, if it causes more severe illness or is more lethal.
It is natural for all viruses to mutate, as their genetic material undergoes small changes during outbreaks.
In fact, more than 10,000 mutations of the novel coronavirus, known as SARS-CoV-2, have been reported, Levon Abrahamyan, a virologist at the University of Montreal, told Global News.
But what makes the U.K. variant more transmissible?
Biologically, certain mutants give the spike protein of the virus — which is responsible for cell entry — a higher affinity for the receptor molecule on a healthy cell membrane, meaning the virus latches on to the human cells more effectively.
“If the attachment of a virus to the receptor is more efficient then this mutant can more readily infect more cells and that can be an explanation of why these mutants are more efficient in infecting and spreading transmission,” Abrahamyan explained.
Colin Furness, an infection control epidemiologist and assistant professor at the University of Toronto, likened the coronavirus to a “master key” that wants to unlock and open different cells across our body.
“It signals the cell to open up and let it in,” he told Global News.
“So rather than having to get in the lock and jiggle a few times to open, this master key is popping the door open really easily, even though it wasn’t designed for that specific lock.”
And then, it is far more likely to stick, Furness said, like a “better velcro.”
Social and behavioural factors can also influence a certain variant’s probability to infect people, Abrahamyan said.
“Superspreader” events like large family gatherings, funerals, festivals, night clubs or football matches, as well as a high level of travel, can also cause the virus to transmit easily, he added.
A new survey by the U.K.’s Office for National Statistics (ONS) published on Wednesday found that people who had tested positive for the new variant were more likely to report coughing, sore throat or fatigue as symptoms of COVID-19.
If people are coughing more, then there is a higher likelihood for them to spew respiratory droplets. Furness said this could possibly be a reason why the variant is more likely to get people sick.
But Abrahamyan said more data is needed to draw any serious conclusions on that theory.
A number of labs across Canada are testing and studying samples for different coronavirus variants. That involves genome sequencing — an expensive, complex process that takes days.
The U.K. variant, for example, can be detected by looking for specific mutations of the virus. That result still needs to be confirmed by sequencing the whole genome.