Ontario is now in the seventh wave of the pandemic and is governed by the BA.5 sub-variant.
The latest mutation, involving the Omicron variant, has led to a rapid increase in cases in Ontario and renewed concerns about a possible revival of public health measures.
Here’s what you need to know about BA.5 and Ontario’s newest wave:
So what exactly is the BA.5 subvariant?
The subvariant was first discovered by scientists in South Africa in January and has been officially tracked by the World Health Organization since April. It has already led to a resurgence of viral activity in a number of countries, including Portugal, the United Kingdom and the United States. The good news is that it is not thought to cause more severe disease than earlier strains of Omicron, but it can be more contagious. In Ontario, the percentage of samples identified as BA.5 after whole-genome sequencing has risen from 14.8 per cent at this time last month to an estimated 66 per cent as of July 6, and is now being blamed for the first summer wave in Ontario since the start of the pandemic.
“I think the fact that it quickly became dominant is a way of showing how contagious it is,” Dr. Karen Bourne, who is assistant science director for the Ontario Science Advisory Board, told CP24.com this week. “We’re learning more about BA.5 every day, there’s just a huge amount of research going on with it, but early studies show that it replicates faster than previous strains and replicates faster in the body, making it very efficient and much more contagious.”
What does it do with the show?
Most experts agree that Ontario is now in the seventh wave of the pandemic, driven by the BA.5 subvariant. The science table said the wave probably started on June 17, although there is no real consensus on when it might peak. The number of people hospitalized with COVID-19 in the past month has increased by about 52% to 712, according to the latest figures released by the Ministry of Health on July 7. However, the burden on the healthcare system is nowhere near what it was during the initial Omicron wave in January, when more than 4,000 patients were hospitalized with COVID-19. Most experts agree that Ontario is unlikely to see thousands of COVID positives in hospitals during this wave, but there are concerns about how well the health care system is equipped to respond to even a modest increase in patient numbers.
“The challenge is that this wave comes at a time when the health care system remains very fragile, very lagging and its summer vacations, so nurses, doctors and other health care workers are all taking time off,” Bourne told CP24.com. “You know, the system is potentially at a point where it lacks capacity for, you know, a huge surge of increased demand.”
Are existing BA.5 vaccines still effective?
Yes and no. The scientists pointed to several mutations in BA.5 that could help it evade the body’s immune response, either from a vaccination or a previous infection. That may explain some of the increased transmissibility associated with the virus, experts say. There was also a study published this week that found that vaccination or recovery from a COVID-19 infection before 2022 already provides little or no protection against re-infection in the Omicron era. However, vaccination is still believed to be highly effective against hospitalization and death, even in the BA.5 era.
“Basically what it does is it just removes some of the protective immunity that we may have acquired from vaccination or from recovering from infection, so people are prone to infection or re-infection, even in those who have been vaccinated or who have been infected in the past,” infectious disease specialist Dr. Isaac Bogoch told CP24.com this week. “That doesn’t mean everyone will get infected. This by no means means that we are back to square one. It just means that one component of the immune system, the antibody response, is not protecting us as well as we once were in terms of getting this infection.
What about quick tests?
Ontario Health Chief Medical Officer Dr. Kieran Moore said this week that later variants of Omicron, including the BA.5, affected the sensitivity of a standard rapid antigen test, reducing sensitivity to 50 to 60 percent. Moore said you can assume you have COVID-19 if you test positive, but a negative test is not enough to conclude you are free of COVID.
If BA.5 is so different, why isn’t it classified as a problem variant?
There are now five sub-variants in the Omicron era, and despite the remarkable genetic mutations that make each one slightly different, Bogoch said they all seem to “fall under the same umbrella.” He said he’s heard some people “muttering that BA.5 is quite far from BA.1 and BA.2,” but he doesn’t believe how the virus is classified makes a huge difference.
“There are some subtle nuances about the BA.5 that make it different from the others. But really, the public health message is still the same. Nothing has changed in terms of how best to protect yourself and those around you from the virus,” he said.
Who is most at risk of BA.5 infection?
Bogoch said the experience of other countries shows the same people were at risk during the pandemic, particularly older Ontarians and people with underlying health conditions. But he said there is also an increased risk factor for individuals who are not fully up-to-date on their vaccinations. That, of course, could be a problem in Toronto, where only about 54 percent of eligible residents received a third dose.
“I think there are some misconceptions that members of the public have, like, ‘I’ve had COVID, I had COVID in 2020, and I’m not going to get it again.’ That’s just not true,” Bogoch told CP24.com.
Could this wave lead to a revival of some public health restrictions?
Dr Moore told reporters this week that he was not “considering recommending further public health measures to the Government” at this time. He said if BA.5 causes a spike in transmission to the point where the province’s health system is at risk, he will act, but he doesn’t expect to have to. Meanwhile, Bogoch told CP24.com that the threat posed by BA.5 can be better addressed through “honest and effective” communication with the public rather than legislation.
“We are talking about communication to support positive human behavior. But that doesn’t mean a press conference at 3:00 in the afternoon to say “hey everyone, it’s a wave, put your mask on.” You actually have to have a dedicated communication strategy and build trust in the communities,” he said. “We talk about it like it’s just virology, public health and medicine, but it’s not.” If you really want to create safer communities and protect Canadians better, that really involves using the expertise of social scientists and having meaningful community outreach and meaningful communication strategies, because a big part of that is making sure people take the steps , which they must do to protect themselves and those around them.”
Will a BA.5-specific vaccine be approved?
Several manufacturers are racing to develop new vaccines that specifically target the Omicron variant. Moderna is believed to be finalizing regulatory filings for its bivalent vaccine, which combines part of the original mRNA formula with a new, updated version designed to better neutralize Omicron. Clinical trial data published last month revealed that the vaccine is more effective against BA.5 than the currently approved booster shot. However, the data show a reduced immune response against BA.5 compared to BA.1. Speaking to reporters this week, Moore said Ontario expects to have access to updated vaccines in the fall, but is still seeking “clarity” on “what the components of the fall vaccine will be.”
“If it’s going to be a BA.4 or a BA.5 (specifically), I expect they’ll have to ramp up production and it could be delayed somewhat, so maybe in November or December,” he said.
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