Regina researchers believe new COVID-19 subvariants could be behind spike in wastewater viral load

New subvariants of COVID-19 that are spreading rapidly in many countries could be responsible for a large spike in viral load found in Regina's wastewater.

On Monday, researchers at the University of Regina posted that the city's viral load had jumped significantly in the past week and was now considered high.

Researchers regularly take samples from sewage plants in Saskatchewan cities and look for evidence of COVID-19. The information is shared with the Saskatchewan Health Authority and can be used to predict whether case numbers are expected to rise or fall.

University of Regina molecular biologist and researcher Tzu-Chiao Chao said the Omicron BQ1.1 and BQ1.11 subvariants had been identified in samples sent to the National Microbiology Laboratory in early September.

Chao said the city's sharp spike in viral load could be linked to the new subvariants.

"It's most likely the BQ variants, because we know they're already there," said Chao. 

"It's also been able to displace BA.5 in other areas. So, that's just an educated guess that it is most likely what's happening right now."

LISTEN | Virologist Angie Rasmussen spoke with host Stefani Langenegger on The Morning Edition:

Chao said it was difficult to predict whether cases will continue to rise or will begin to plateau.

He said the latest available data was taken right before the Thanksgiving long weekend. Considering the level of gathering that happened that week, Chao said he would like to see more recent data before making any predictions.

Chao said he didn't have a current breakdown of the percentages of COVID subvariants that make up Regina's wastewater samples and was waiting for new information from the National Microbiology Laboratory.

New variants

Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization (VIDO) at the University of Saskatchewan said both BQ 1.1 and BQ 1.11 are believed to be very infectious.

While the new subvariants don't appear to cause more severe disease in high-risk people, Rasmussen said it would be a mistake for people to let their guards down.

"As the weather gets colder and colder, people are spending more and more time inside," she told CBC Radio's The Morning Edition. 

"We've also relaxed a lot of the precautions that were in place to reduce transmission."

Rasmussen said that she expects more hospitalizations for high-risk people and more severe illness in general this winter, due to the new subvariants and a potentially bad flu season hitting at the same time.

She said the arrival of new bivalent booster vaccines in the province will help. Rasmussen said the new boosters are designed to protect against Omicron.

"Not a lot of people have actually gone out to get them yet," she said.

"My recommendation to everybody would be is, if you want to face this with the most protection that you can possibly have, go out and get your bivalent booster if you are eligible for it."

The virologist also said wearing masks while indoors in public settings continues to be a good way to slow the spread of COVID-19.