Delta strain now dominant COVID-19 virus variant of concern in Manitoba

The delta variant, which has driven fourth waves of the pandemic around the world, is now the dominant coronavirus variant of concern involved in COVID-19 cases in Manitoba, a provincial spokesperson said in an email. 

During the last week of July, COVID-19 cases stemming from the delta, or B.1.617.2, variant made up 33.7 per cent of variant of concern cases in Manitoba. Cases related to the alpha variant, also known as B.1.1.7 — previously the most common variant-driven cases in the province — made up 20.5 per cent. 

As of Tuesday, there have been nine deaths in Manitoba linked to the delta variant of the coronavirus that causes COVID-19, the province's online variant dashboard says.

The province also has reported three cases of a delta subvariant called AY.3, which is sometimes called "delta plus." One of those cases was considered active on Friday.

The highly contagious delta variant has been the driving force behind a fourth wave of the pandemic in several countries, including the United States, where some regions have reimposed mask mandates due to climbing cases and hospitalizations. 

In light of this, some have criticized the province for getting rid of many of its pandemic restrictions, including mask mandates, saying Manitoba will most likely be in the same situation this fall. 

Provincial officials have been asked for weeks about local disease modelling predictions that take into account the delta variant, but as of Monday, the province has yet to publish them. 

Dr. Jazz Atwal said Monday that officials are currently reviewing the modelling data and when that's done, it will be released to the public.

It's likely that Manitoba will see the same trends as the rest of the country, said Prabhat Jha, a professor of global health at the University of Toronto.

Jha said the delta variant has become known as the Chuck Norris of strains, as it "kicks the other variants' butts around, because it's more efficient in transmitting." (Norris is an American martial artist and actor who is famous for his roundhouse kick.)

It also has the ability, in some cases, to transmit among vaccinated people, he said. 

"And therefore, it's going — it has pretty much become — the dominant strain worldwide."

Not much is known about the delta plus subvariant at this point, Jha said, and until scientists understand the risks, it's important to focus on containing the problem variant we know.

Scientists estimate delta is spreading roughly 50 per cent faster than the alpha variant, which was 50 per cent more contagious than the original virus strain, according to the Yale School of Public Health.

Vaccines offer protection

The good news is that the Pfizer-BioNTech, Moderna and AstraZeneca vaccines have proven effective at preventing severe illness and death, at least among those who are fully vaccinated. 

Other countries, such as Israel and the U.K., which are weeks into a fourth wave, have not seen the same surge in hospitalizations or deaths that were experienced in previous waves of the pandemic, Jha said.

"Cases are going up, but those are not, so that gives us some assurance," he said. 

That being said, if the province sees a huge increase in cases driven by the delta variant, that could lead to pressure on the health-care system. 

"If the number of cases goes really high, then even with a lower complication rate, just the absolute numbers can overwhelm the hospital system," Jha said. 

Just under 81 per cent of eligible Manitobans had at least one dose of a COVID-19 vaccines as of Monday, with 74.3 per cent double vaccinated, according to the province's online COVID-19 vaccine dashboard.