Experts call for COVIDzero strategy to weed out virus, but will it work?

·5 min read

As COVID-19 cases rise steeply across parts of Canada, infectious disease experts are calling for a new strategy to curb the unruly spread of the virus.

The proposed goal is simple: whittle down case counts to zero, or at least close to it.

But doctors say it will be far more complicated to figure out how to reach that target, with some skeptics casting doubt as to whether it's even realistic.

Advocates have taken to Twitter this week urging Canada to embrace an elimination-style strategy under the hashtag COVIDzero.

The aim of the approach is to wipe out the virus through stricter restrictions ranging from targeted closures to full-on lockdowns, bolstered testing and tracing capabilities and government relief for individuals and businesses.

While skeptics believe in the concept behind that idea, they worry it may fall short in execution.

"The goals are important — aiming for a low case number, an appropriate testing strategy, supporting people through contact tracing and isolation —that should be a part of our response," said McMaster University's Dr. Zain Chagla.

"But I don't think we can plausibly achieve zero. And we have to be very, very careful and transparent about what this (strategy) would entail."

Dr. Irfan Dhalla, an associate professor at University of Toronto who is among many doctors advocating for COVIDzero, has been arguing for an elimination strategy for months.

But he says the timing now is "urgent" as Canada's average daily counts have climbed into the 5,000-range, and hospitals have begun facing "significant challenges" with overwhelmed intensive care units.

"We need more restrictions on activity than we have," Dhalla said. "But we don't necessarily need to prolong a lockdown."

Dhalla says places around the world have been successful in containing the virus by implementing elimination-type strategies, including Australia, New Zealand, Thailand and even Canada's Atlantic bubble.

While a lengthy lockdown was needed in some of those areas — Melbourne had a strict shutdown lasting more than 100 days — Dhalla also pointed to places like South Korea, which relied on testing and tracing rather than a full lockdown, to show that it is possible.

Dr. Isaac Bogoch of the University Health Network "strongly doubts" a COVIDzero strategy can be achieved in Canada without a lengthy lockdown.

"And even if you do have lockdowns, like we did before, you still won't get to zero unless you address the structural inequities that are driving COVID-19 in Canada," he said.

Bogoch, like Chagla, sympathizes with the spirit of the COVIDzero movement, but questions if it's feasible.

"If indeed you want to take an elimination strategy, it's important to know what that involves," Bogoch said. "At the end of the day, you can have all the hashtags and platitudes you want on social media. But there are very challenging hurdles to overcome to get to (a COVID zero) state."

He said one of the most significant obstacles will be convincing leaders at all levels of government to agree on a consistent message.

Officials would also have to provide "tremendous support" to businesses and low-income, marginalized workers to make up for lost revenues and employment cuts, said Bogoch.

There are also travel restrictions to consider, he said, pointing out that people in Melbourne were allowed only a five-kilometre radius for leaving their homes for essential purposes.

Canada had nearly 51,000 active cases as of Tuesday afternoon and more than 11,000 deaths since the pandemic began earlier this year.

Dhalla says that's inexcusable at this stage in the pandemic.

"We're losing several dozen Canadians every day to this virus, that at this point, we know how to prevent," Dhalla said. "And we're struggling in some hospitals, where we simply cannot provide the quality of care that we would like."

Chagla agrees that pressure on hospitals needs to be lifted, noting that other plans of action have been brought forward recently to deal with the surge.

Some have argued for shorter "circuit breaker" lockdowns or targeted closures, while others have advocated for rapid testing to weed out new infections.

Chagla says a targeted closure approach appears to be working in Ottawa, where the spread has slowed down recently. But that may not translate to other hotspots like Brampton, Ont., where the positivity rate in some neighbourhoods is close to 20 per cent.

A period of lockdown could alleviate some of the strain on hospitals and contact tracing capacities, he said. But how close to zero cases would we need to get to before restrictions could lift?

Dhalla said it's "less about a number than it is about the trajectory," using Toronto's daily average of 500 new cases as an example. As long as the number is increasing, restrictions would remain.

While Chagla concedes that a full lockdown is "likely on the table at some point," he says we need to work harder this time to fix the root of transmission.

He estimates it would take five or six months of a full lockdown, while also boosting testing and tracing, for Canada to get to a truly zero state.

"I wish there was a simple answer to this," he said. "But the thing is when you just do a lockdown and you don't address problems in those communities, you're going to see the same issues after the lockdown is over."

This report by The Canadian Press was first published Nov. 17, 2020.

Melissa Couto Zuber, The Canadian Press