'It's the real deal': Doctors warn about future wave fuelled by Omicron variants

COVID-19 cases are rising again in Canada, with the two fast-spreading Omicron subvariants to blame, otherwise known as BA.4 and BA.5 variants.

First detected in South Africa in April this year, their ability to spread more quickly than other circulating variants, primarily BA.2, has led to scientists predicting their prevalence as the dominant variant in approaching months.

Canadian researchers examining the threat of emerging COVID-19 strains predicted that the Omicron BA.5 would account for nearly 70 per cent of cases by Canada Day. The latest Public Health Agency of Canada data, which goes back to June 12, shows that BA.5 made up 20.4 per cent of COVID-19 cases.

• Newsletter sign-up: Get The COVID-19 Brief sent to your inbox

Sarah Otto, a University of British Columbia professor and modelling expert at the Coronavirus Variants Rapid Response Network, predicted a July wave peaking in August.

"The last sequence data was mid-June, but the projections for July 1 would be: roughly 13 per cent (of cases are) BA.4, and 69 per cent BA.5," said Otto in an interview with The Canadian Press.

"I'm referring to it as a third Omicron wave because I've lost count of all of the other waves."

• CTV News app sign-up: Breaking news alerts and top stories delivered right to you

The most recent Omicron variants appear to be causing fewer hospitalizations and fatalities than their older counterparts, which could be attributed to high vaccination levels and potential herd immunity, according to infectious disease specialist Dr. Isaac Bogoch.

“I think we have to take a step back and remember that the vast majority of Canadians have been vaccinated. So we do have a lot of community-level protection from immunity through vaccination," Bogoch told CTV’s Your Morning on Monday.

But, as cases of subvariants rise, it’s hard to predict if this trend will continue.

“(We’re) starting to see an uptick in, for example, wastewater surveillance, the percentage of tests that are positive and in certain parts of the country even started to see a small, real uptick in the number of people in hospital,” he said.

“So it's the real deal. We're having, you know, a summer wave. And, it's not quite clear how big this wave will be. But we certainly are having more cases now than we did a few weeks ago.”

There are also rising concerns about whether hospitals can handle a rise in cases, as emergency rooms across the country are currently facing unprecedented wait times, with some even facing shutdowns.

“The health-care system took a real walloping during this pandemic, and it never fully recovered,” Dr. Christopher Labos, a Montreal-based epidemiologist and cardiologist, told CTV News Channel on Monday.

“You have staff shortages, you have people who are burned out, and you're starting to see emergency rooms being forced to close for weekends or evenings because of staff shortages. And all this is happening in the context of more and more patients getting sick and more and more patients ending up in the hospital,” he added.

“Things are not OK.”

Labos says that the only way forward is for an Omicron-specific fourth vaccine dose to be released to all members of public, which should prevent severe sickness and give hospitals in the country a slight reprieve.

“I think we are going to need a booster to get us through the next few months because while we were expecting a wave, the fact that it's coming this early has sort of skewed plans a little bit,” he said.

“The fact that cases are surging now has changed the calculus on that a little bit, and so if cases stay low, you might be better off waiting for that moment on a specific Omicron vaccine which might come out in October, maybe November.”

Eligibility for fourth doses vary among provinces, although most are only offering second boosters to older adults and others deemed to be at higher risk.

Bogoch says that while the newer subvariants are much more transmissible than other strains, it remains unclear if they’re more dangerous or injurious to people’s health.

The easiest way to remain safe is to be up-to-date with COVID-19 vaccinations, Bogoch says, which will reduce the chances of getting sick and potentially eliminate the odds of hospitalization if one does get sick.

Otto noted that BA.4 and BA.5 appear to primarily infect the upper airways – versus the lower lungs – leading to less severe cases on average than pre-Omicron variants.

"My prediction is that the cases are going to go up, hospitalizations are going to go up, but my current hope is that it won't be as bad as the BA.2 wave," Otto said, adding there was not enough data yet to know for certain.

At the pace BA.5 has been growing, she said BA.5 is now about five times more common in Canada than BA.4.

"Pretty soon, it will just be the BA.5 wave."

With files from Canadian Press