How Canadian researchers use genome sequencing to track coronavirus variants

Toronto - Infectious disease researchers at McMaster University in Hamilton use genome sequencing to track new COVID-19 variants. There are now a number of cases in Canada of a highly infectious type of coronavirus first discovered in the UK in September.

Researchers say they were able to identify the new variant through genome sequencing, which provides genetic information about the organism's DNA.

Dr. Andrew MacArthur, an associate professor and computational biologist for infectious disease research at McMaster University, said in an interview on the Canadian CTV channel on Wednesday, "Everything about the biology of the virus is controlled by its DNA. Even the way we use to diagnose you when we do a nasal swab depends on the DNA, like the polymerase chain reaction test."

He added, "The more you study this DNA, the more you understand its biology, how it infects people and how it moves." He added, "All pathogens change over time and become diverse and have strains or variants, so you constantly have to conduct surveillance to make sure there are no scary traits in any of these variants."

Only about 5 percent of cases in Canada are screened for different variants. Since genome sequencing is much more expensive than clinical COVID-19 testing, MacArthur says Canada cannot isolate every positive COVID-19 case to check for the new variant. For this reason, he suggests that researchers work with epidemiologists to build a strong surveillance strategy. We know this virus spreads and is hard to contain.

MacArthur says, "There is no real surprise in its global spread." "This particular type in the UK has 23 mutations, which is a much higher rate than we are used to seeing."

With new vaccines approved and rolled out globally, there are questions about how they work with different strains of coronavirus. Some researchers wonder whether these variants can outsmart vaccines that took months and billions of dollars to make. "Since we have been fighting this for a long time, we have the skills for rapid assessment. This strain does not seem to have become severe, but initial evidence suggests it is more infectious and would be difficult to control," MacArthur says. "So you really need to respond quickly."

On December 20, Canada announced it would temporarily ban travel from the UK to help stop the spread of the new strain. The travel ban was then extended later until at least January 6, 2021.