Fast-spreading Omicron sub-variant BA.2 taking hold in Sask.

The Omicron sub-variant BA.2 makes up 10 per cent of all COVID-19 cases in Saskatchewan and is poised to take over as the new dominant strain, according to an expert.

BA.2 is up to 30 per cent more transmissible than the original Omicron, said Joseph Blondeau, head of clinical microbiology at Royal University Hospital and University of Saskatchewan.

“If you put it into mathematical terms, an infected individual would be expected to infect four more people. Those four would infect 16, those 16 would affect 256, and those 256 would infect 1,024, and so it goes, and so it means that it can spread much more quickly through the population.”

Blondeau says people tend to have milder symptoms with this variant with fewer admissions to the ICU compared to the Delta variant, but that may be offset by how transmissible it is.

According to the University of Saskatchewan wastewater surveillance team, the viral RNA load in Saskatoon’s wastewater has increased by 66.3 per cent. The breakdown of strains was: non-Omicron 26.5 per cent; Omicron BA.1 39.4 per cent; and Omicron BA.2 34.1 per cent.

"The trend over the last three weeks has been increasing which indicates a double wave for the Omicron wave driven by the BA-2 subvariant," Monday's update says.

Virologist Jason Kindrachuk says the cost-benefit ratio of restrictions to slow the spread of the BA.2 variant is difficult to measure because researchers don’t know exactly what the variant will do in Canada with different rates of vaccinations and immunity.

“Most of what we're seeing right now coming out of Europe is certainly telling one story, right, it's increasing,” he said.

“We're seeing that as people remove restrictions, cases are increasing. Whether that is what we're also going to see is in Canada is a bit of a question mark. If we give the virus room it probably is going to transmit, but we have to appreciate that there are going to be some regional differences too.”

Kindrachuk says it’s also important to strike a balance between the rollback of restrictions and the strain that could put on the healthcare system.

“We don't have an algorithm that we use to plug data in, and that can say, 'Okay in the next few weeks, things are going to go completely off the tracks.' A lot of it is just being fluid. That's difficult because when you remove the restrictions, now if you need to re-enable them, you have to still have that trust in the public and that transparency, where people still feel that there is a need.

"We just need to keep up messaging we need to keep up doing a lot of work surveillance-wise.”

Kindrachuk stressed that the pandemic is not over, and people still need to be vigilant despite a lack of mandates and restrictions in Saskatchewan.

“Now is the time that if we are you noticing that anything feels different, if we're feeling a little bit more lethargic or feeling tired or feeling a little bit under the weather, we don't risk it,” he said.

Blondeau says vaccines don’t have 100 per cent efficacy against COVID-19, but they are the way out of the pandemic.

The risks of hospitalization and death from COVID-19 both decrease with a third shot, he said.

“Our way forward is still the vaccine, and there may be a day when we're encouraged to get a fourth shot, and my message wouldn't change. Get in line.”