Ontario is now in a seventh wave of the pandemic and is being driven by the BA.5 subvariant.
The most recent mutation involving the Omicron variant has led to a rapid increase in cases in Ontario and has renewed concern about the possible reactivation of public health measures.
Here’s what you need to know about BA.5 and the latest wave of Ontario:
So what exactly is the BA.5 subvariant?
The subvariant was first detected by South African scientists in January and the World Health Organization has been formally monitoring it since April. It has already caused a resurgence of viral activity in several countries, including Portugal, the United Kingdom and the United States. The good news is that it is not believed to cause more serious disease than previous strains of Omicron, but it could be more infectious. In Ontario, the percentage of samples identified as BA.5 after whole genome sequencing has increased from 14.8% at this time last month to about 66% on July 6 and is now accused of having caused Ontario’s first summer wave since the start of the pandemic.
“I think the fact that it has quickly become dominant is a way to show how contagious it is,” Dr. Karen Born, who is the deputy scientific director of the Scientific Advisory Board, told CP24.com this week. Ontario. “We are learning more about BA.5 every day, there is only a large volume of studies on it, but early studies show that it replicates more quickly compared to previous strains and that it also replicates more quickly in the body., making it very efficient and much more contagious. “
What are you doing with the transmission?
Most experts agree that Ontario is now in a seventh wave of the BA.5 subvariant-driven pandemic. The scientific panel has said the wave probably started on June 17, although there is no real consensus on when it could reach its peak. The number of people hospitalized with COVID-19 over the past month has risen by about 52 percent and now stands at 712, according to the latest data released by the Ministry of Health on July 7th. However, the burden on the healthcare system is nowhere near what it was during the initial wave of Omicron 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-positive individuals in hospitals during this wave, but there are concerns about how well-equipped the health care system is to respond to even a moderate increase in the volume of patients.
“Demands on this system from this wave of COVID-19 are not expected to be as high as some of the previous waves, but it is nonetheless hitting a healthcare system that is weakened by the two years of the pandemic and a backlog. Born told CP24.com, adding: “So, you know, the system is potentially at a time when it doesn’t have the capacity to, you know, a big surge of the demand “.
Existing vaccines still work against BA.5?
Yes and no. Scientists have noted several mutations in BA.5 that could help it evade the body’s immune response, either from vaccination or from a previous infection. This could explain part of the increase in transmissibility associated with the virus, experts say. A study was also published this week that found that vaccination or recovery from a COVID-19 infection before 2022 now offers little or no protection for re-infection in the Omicron era. However, vaccination is still believed to be extremely effective against hospitalization and death, even in the BA era.5.
“Basically, what it does is eliminate some of the protective immunity we could have gained with vaccination or recovery from infection, so that people are prone to infection or reinfection, even in those who were 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 gets infected. That doesn’t mean we’re back in the case. It just means that one component of the immune system, the antibody response, doesn’t protect us as well as we were protected before in terms of get this infection “.
What about quick tests?
Ontario Medical Director of Health Dr. Kieran Moore said this week that later variants of Omicron, including BA.5, have affected the sensitivity of a standard rapid antigen test, reducing the sensitivity between 50 and 60 percent. Moore said you can assume you have COVID-19 if you test positive, but a negative test is not enough to conclude that you are free of COVID.
If BA.5 is so different, why has it not been classified as a variant of concern?
There have now been five subvariants in the Omicron era, and despite the remarkable genetic mutations that make each one a little different, Bogoch said it seems they all “fall under the same umbrella.” He said he has heard some people “growl that BA.5 is quite far from BA.1 and BA.2,” but he does not think the virus classification is very important.
“There are some subtle nuances associated with BA.5 that make it different from others. But really the public health message remains the same. Nothing has changed in terms of the best way to protect yourself and those around you from the virus, ”he said.
Who is most at risk for a BA.5 infection?
Bogoch said the experience of other countries suggests that they are the same people who have been at risk during the pandemic, specifically older Ontarians and people with underlying health conditions. But he said there is also an increased risk factor for people who are not fully up to date with their vaccines. This, of course, could be a problem in Toronto, where only 54% of eligible residents have received a third dose.
“I think there are some misconceptions that members of the public have where it’s like‘ I had COVID, I had COVID in 2020 and I won’t have it again. ’That’s not true,” Bogoch told CP24.com.
Could this wave end up leading to the reactivation of some public health restrictions?
Dr. Moore told reporters this week that he is not “considering recommending to the government any other public health measures” right now. He said if BA.5 causes an increase in transmission to the point that the province’s health system is threatened, it would act but does not plan to do so. Bogoch, for his part, 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 talk about communication to help drive positive human behavior. But that doesn’t mean a press conference at 3pm saying, ‘Hello everyone, this is a wave, put on your mask.’ have a dedicated communication strategy and build trust in communities, ”he said. “We talk about this as if it were just virology and public health and medicine, but it’s not. If you really want to create safer communities and better protect Canadians, it really involves using the experience of social scientists and having meaningful outreach. significant community and communication strategies, because much of this ensures that people take the steps they need to take to protect themselves and those around them. ”
Will a specific BA.5 vaccine be approved?
Several manufacturers have been struggling to develop new vaccines aimed more specifically at the Omicron variant. Moderna is believed to be finalizing regulatory presentations for its bivalent vaccine, which combines part of the original mRNA formula with a new updated version designed to better neutralize Omicron. Data from clinical trials published last month revealed that the vaccine is more effective against BA.5 than its currently approved booster vaccine. However, the data showed a decreased immune response against BA.5 compared to BA.1. Speaking to reporters this week, Moore said Ontario plans to have access to updated vaccines in the fall, but is still looking for “clarity” on “what the components of the fall vaccine will be.”
“If it will be BA.4 or BA.5 (specific), I anticipate that they will have to increase production and it could be delayed a bit, so maybe November or December,” he said.