There are early signs that Canada is already entering a fall wave of COVID-19, while updated booster shots are likely weeks away.
Earlier this week, the Public Health Agency of Canada He said fluctuations in virus activity across the country could be an “early sign” of rising infections.
The percentage of COVID tests that came back positive, for example, had been gradually declining since the spring, but began to rise again over the past month, recently reaching nearly nine percent. Hospitalizations also increased in August, jumping about 11 percent in one week, as the number of hospital beds occupied by COVID patients reached more than 1,700 by August 15.
Sewage signals across Canada are also increasing. As of the end of July, at least seven of the 39 sites tracked by federal officials reported an increase, and that number has since nearly doubled to at least 13.
Western University microbiologist Eric Arts said wastewater from Ontario in particular is showing an increase in virus samples, but with low reporting and limited testing in much of the country, the whole picture is confusing. What is clear, added Arts, is that the number of cases in the US is already increasing “drastically”, which means that the wave of Canada is not far behind.
“We all hear, myself included, anecdotal evidence of new infections from people we know,” he said.
Decreased immunity, new subvariant may play a role
According to experts, the size of Canada’s fall surge will largely depend on the level of immunity of the country’s population, as well as the timing of fall booster vaccinations that are not yet approved in either Canada or the US. .us
“Our COVID numbers are teetering up and down as we balance transmission with immunity,” said researcher and epidemiologist Caroline Colijn, Canada 150 Research Chair in Mathematics for evolution, infection and public health at the Simon Fraser University.
As Breaking: recently reported, research shows that the majority of the population has developed some level of immunity against SARS-CoV-2, thanks to high vaccination rates and the fact that three-quarters of Canadians likely have detectable antibodies linked to previous infections. Hybrid immunity, developed through a combination of prior vaccination and infection, is believed to be a particularly strong form of protection.
But while many people’s immune systems are now better able to recognize this threat, lower rates of serious illness and death Over the course of the pandemic, the level of protection needed to prevent another infection in the first place may fade over time.
“We haven’t had a big wave of COVID in the summer and we haven’t had a lot of vaccinations. So that protection against infection might have gone down to some degree,” Colijn said. “And that puts us in a position for a potentially bigger wave.”
A contagious subvariant called EG.5 that is widely circulating right now could also help fuel a surge, though scientists are still assessing the risks posed by the Omicron offshoot.
early evidence suggests that it is not more serious, but seems better able to evade front-line immune defenses, allowing it to infect and re-infect more people.
There is no reason to panic, Colijn stressed. But among people who may not have an infection or a booster shot for months, a fast-spreading subvariant can find many new hosts.
“You don’t need a lot more severity to cause a big problem if you have a lot more numbers,” he warned.
‘Our system is fragile’
Challenges from another wave would hit Canada on multiple fronts, said Dr. Donald Vinh, an infectious disease specialist and associate professor in the department of medicine at McGill University.
For one, more COVID infections would increase pressure on the health care system through increased demand on hospitals, along with higher rates of sick health workers, Vinh said.
“That combination can become problematic. We know that our system is fragile,” he said. “And we’ve dealt with this fragility of a surge in community COVID cases before…but the health care system can’t take that many.”
In terms of the direct impact on patients, Vinh said that while high levels of hybrid immunity should prevent many life-threatening diseases, there is also the potential for lasting health impacts from initial or repeat infections, including prolonged COVID.
Booster shots could bolster Canadians’ immunity this fall, particularly as drugmakers have tailored their vaccines to better match strains currently circulating, but Vinh cautioned that the “cycles are out of sync.”
The United States, which typically approves new vaccines faster than Canada, has yet to approve new formulations and close watchers don’t expect those approvals until late Augustwith distribution sometime after that.
“The timing is not the best,” Vinh said. “Because if we anticipate the US to have its release in late September, or maybe early October, realistically, in Canada, we’re probably looking at maybe mid to late October, or God forbid, even a little later.”
Experts Recommend Boosters, Basic Precautions
Canada’s national vaccine advisers have it is already recommended to obtain an updated dose once fresh vaccines arrive, especially if you are at higher risk for serious illness, including people age 65 and older, people living in long-term care homes, people who are pregnant, and anyone with medical conditions underlying medical conditions.
Those national guidelines also suggest waiting about six months after a prior vaccine dose or known SARS-CoV-2 infection, as research suggests injections are most effective when spaced apart from active infection or prior vaccination. as Breaking: has previously reported.
While the shots offer long-lasting protection against serious illness, Arts said there is a downside to waiting. also time between doses: “We know that the longer we go without a booster, the more likely that if we are exposed, we will become infected.”
The next few shots could help mitigate the end of a wave of COVID, he added, “but it’s not going to prevent this wave now.”
Vinh said Canadians can also bring back basic precautions in the coming months, such as avoiding crowded indoor places, wearing a mask and staying away from others when sick, while businesses can consider increasing indoor ventilation as much as possible.
However, even at this point, Colijn stressed that we are in a better place than the US heading into the fall, given the higher levels of vaccine acceptance in Canada in recent years, so an increase in cases reflecting the increase south of the border is not inevitable.
“Whether it turns into a big wave or not,” he said, “we’ll have to see.”