Cassandra Szklarski, The Canadian Press Published Thursday, June 30, 2022, 11:17 a.m. EDT Last updated Thursday, June 30, 2022, 3:07 p.m. EDT
Researchers studying the threat of emerging strains of COVID-19 predict that Omicron BA.5 will account for nearly 70 percent of cases by Canada Day.
Modeling expert Sarah Otto of the Coronavirus Variants Rapid Response Network says the fast-spreading subvariant is on track to dominate infections across the country.
A professor at the University of British Columbia predicts a July wave with a peak in August.
“The last sequence data was from mid-June, but the predictions for July 1 will be: approximately 13 percent (of cases are) BA.4 and 69 percent BA.5,” said Otto, one of the heads of computational biology and modeling at arm of the network, also known as CoVaRR-Net.
“I’m calling this the third Omicron wave because I’ve lost count of all the other waves.”
The head of Ontario’s COVID-19 advisory group also suspects that BA.5 is the main driver nationally and pointed to several indicators that suggest it is already responsible for more than half of the reported cases in his province.
Dr Fahad Razak said the strain was particularly capable of evading immunity from vaccination and previous infection, leading to “very rapid growth”.
A national breakdown of the variants by the Public Health Agency of Canada noted a dramatic jump earlier this month, with BA.5 responsible for 14.6 percent of COVID-19 cases identified by whole-genome sequencing as of June 5, up from 7 .1 percent the previous week.
Quebec Public Health Director Dr. Luc Boileau said Wednesday that BA.2.12.2 remains the dominant strain in that province, but that BA.5 is gaining ground faster than others. These two Omicron cousins, combined with BA.4, account for more than three-quarters of the infections in Quebec.
Here’s a look at what we know about BA.5.
IS IT HARDER?
It appears to be no more or less severe than previous strains, Razak said, but several questions make it difficult to say whether a spike in BA.5-fueled cases will also affect hospitalizations.
He noted that Canada’s population now boasts a mix of two, three and four doses of vaccines — different vaccines are used depending on eligibility and the timing of vaccinations varies, which affects today’s immunity. Meanwhile, the recent spike in infections has further strained immunity, with perhaps half of Canadians or more infected in the past six months.
“It makes it very difficult to know what’s going on when you have this subvariant that’s mutated but is still part of the Omicron family as it emerges.” Will it cause another increase in hospitalizations? I think it’s very hard to say,” Razak said.
Otto noted that BA.4 and BA.5 seem to primarily infect the upper respiratory tract — versus the lower lungs — resulting in milder cases on average than the pre-Omicron variants.
“My prediction is that cases will go up, hospitalizations will go up, but my hope right now is that it won’t be as bad as the BA.2 wave,” she said, adding that there isn’t enough data to know yet with security.
At the rate BA.5 is 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,” said Otto, also a member of the British Columbia COVID-19 Modeling Group and the Public Health Agency of Canada’s External Modeling Group.
WHY THIS IS A CONCERN
Although Canadians have higher immunity than ever before, this new sub-variant is fundamentally different from the previous one, Razak said, making re-infection more likely.
“It’s mutated enough that even if you were infected with the original Omicron wave that just came in the spring, the surface of the virus looks different enough that your immune system doesn’t recognize it and another infection happens again.”
Most fully vaccinated people infected with BA.5 experience a mild bout of COVID-19, Razak said, but high-risk groups, including immunocompromised individuals and the elderly, are still at greater risk of severe disease.
Even mild COVID-19 can be very destructive, added Razak, who fell ill despite being triple vaccinated and found it difficult to work.
“I really didn’t feel normal for three or four weeks. And I have many, many friends and colleagues who are in a similar risk category with a very low risk of hospitalization, but the infection has really affected us in terms of our family life, our work lives,” he said.
Then there’s the threat of lingering COVID-19, a still largely mysterious condition in which some symptoms remain months later, such as fatigue, brain fog, shortness of breath and general pain, he said.
WHAT CAN INDIVIDUALS DO?
The best thing a person can do is to get fully vaccinated, stay outside as much as possible when socializing or interacting with others, and wear a mask as much as possible when indoors, Razak said.
“It’s no longer a black and white situation where it’s all or nothing. “Public health measures, a lot of them have been lifted and so you really have to look at how you can as an individual reduce your risk,” Razak said.
“And get vaccinated to the fullest extent possible, knowing that there is likely a new generation of vaccines that are more attuned to Omicron and have greater protection that will be available, potentially as early as the fall.”
Masks can play a role in reducing the impact of BA.5, even if mask mandates have been dropped in many circumstances, Otto said.
“Right now the weather forecast is not great for COVID. And the weather is about to get worse and we need to act accordingly.”
Otto also said now is the time to get familiar with vaccines, especially the elderly, many of whom were boosted in December and January and will have low protection unless they get a fourth dose.
“That would be my only really strong appeal: Anyone who has any health sensitivities, anyone who is older, should get the boosters that are available to them right now to protect them in this coming wave,” she said. .
WHAT NEXT?
Vaccines currently being developed try to match the strains that are currently circulating, Razak said.
“More doses are in our future,” he said.
Razak says the version of the virus circulating now has mutated so much that it is “barely recognizable compared to what appeared two years ago.”
“This is not a failure of the original vaccines. They were very effective at what they had to accomplish. They still give you protection against serious illness, it just means we’ve been able to develop the science to give you something even better. “
Meanwhile, Otto urged public health officials to be candid about what this summer could look like without current infection control measures in place as cases rise.
“I don’t think the public knows that the BA.5 wave really hit us in Canada. Public health officials need to make this much clearer. And they should encourage the public to step up the protective measures that we all know work — masking up, (opening) those windows, socializing outdoors. We just have to be prepared.”
— With files from Morgan Lowry in Montreal
This report by The Canadian Press was first published on June 29, 2022.
Add Comment