05/14/2020 15:37 EDT | Updated 08/10/2020 16:07 EDT

A Second Wave Of Coronavirus In Canada: What You Need To Know

Canada could face a surge of new cases of COVID-19 later this year.

When will the coronavirus outbreak be over in Canada? It will likely not truly be over until after there is  a second wave of infections. 

Public health and government officials are well aware of a recent new spike of cases in countries like China and South Korea, and see it as proof that initially flattening the curve of COVID-19 does not mean the crisis is over. 

Canada’s chief public health officer Dr. Theresa Tam says Canadians should prepare for a “new normal” that will continue even after the current first wave is contained.

Prime Minister Justin Trudeau warned in May that lifting restrictions too quickly could send Canada “back into confinement” if a second wave hits.

Prime Minister Justin Trudeau holds a press conference at Rideau Cottage during the COVID-19 pandemic in Ottawa on May 7, 2020.

“We are still in the emergency phase … the vast majority of Canadians continue to need to be very careful,” he said. 

It’s a sentiment echoed by provincial public health officials too — B.C. chief public health officer Dr. Bonnie Henry said this week that there’s “very much a potential of a surge to come in the fall.”

So what does a second wave look like? And what is Canada doing to prevent it? 

What is a second wave?

Remember that curve that we’re all trying to flatten? That refers to the growth of new COVID-19 cases day over day. The so-called second wave would be another increase or spike of cases after the initial wave of infections stabilized. An epidemic curve can have multiple severe waves or spikes in case rates before it’s stabilized with a treatment or vaccine. 

What’s an example of the second wave?

The Spanish flu pandemic from 1918 could hold the key to how we think about a possible second wave of COVID-19.

The Spanish flu was responsible for the deaths of at least 50 million people worldwide, including 55,000 in Canada. While it first hit in the spring of 1918,  the second wave in the fall that same year was actually far deadlier than the initial outbreak.

Much like right now with COVID-19, governments around the world back then, particularly in the U.S., implemented aggressive physical distancing measures to combat the spread of the virus. Many of the restrictions that seem all too familiar now — bans on mass gatherings, encouragement to wear face covers — were present in 1918, too. And research has shown that the timing of lifting those restrictions was directly tied to the impact of the virus. Cities in the U.S. that kept restrictions in place longer faced fewer deaths in the second wave.

Library of Congress/ASSOCIATED PRESS
Volunteer nurses from the American Red Cross tend to influenza patients in the Oakland Municipal Auditorium, used as a temporary hospital for the 1918 Spanish flu pandemic. 

The research, published in 2007 in the Proceedings of the National Academy of Sciences of the United States of America, found that second waves only occurred once a jurisdiction lifted restrictions. 

“These findings support the hypothesis that rapid implementation of multiple NPIs (non-pharmaceutical interventions) can significantly reduce influenza transmission, but that viral spread will be renewed upon relaxation of such measures,” the authors wrote.

The Spanish flu actually also had a third wave as well, and while it was more deadly than the first, it didn’t compare to the mortality of the second. There was even a fourth wave of the virus, consisting of isolated outbreaks in places like New York City. 

Which countries are experiencing a second wave right now?

Many countries that experienced sharp initial spikes in COVID-19 case rates, then appeared to get them under control are once again seeing an uptick in new infections. 

Singapore went from having fewer than 2,000 cases at the beginning of April to now more than 23,000. The city-state had been able to contain the initial wave of the virus in February and early March with strict quarantine measures and contact tracing, as well as widespread testing.

However, cases started to spike again in April after undetected outbreaks in the area’s migrant worker population began to spiral as restrictions were lifted. Singapore is once again implementing firm quarantines and contact tracing to attempt to contain the second wave.

WATCH: Singapore’s migrant workers form most of its virus cases. Story continues below.


China is rapidly expanding testing and lockdown once again in Wuhan, the city where the outbreak began back in December. Six residents tested positive for the virus over the weekend, ending a 35-day streak without new cases there. The Chinese government has said they will test every citizen in Wuhan in the coming days. A lockdown has also been imposed in the nearby city of Shulan, which reported multiple new cases this week.

On Sunday, South Korean president Moon Jae-In said “it’s not over until it’s over,” as a new cluster of cases emerged in the country. South Korea was heralded as one of the first countries to get the initial wave of the virus under control and start to lift restrictions. 

But there are success stories. Hong Kong is being heralded as the gold standard for preventing a second wave so far, but it comes with aggressive quarantine procedures. The territory is only allowing residents back in, and they are subject to testing upon arrival and throughout a strictly monitored 14-day quarantine that involves a phone app that connects to an electronic bracelet to track their movements. 

How is Canada preparing for a second wave?

Experts say the best way to prevent a second wave of the virus is not to lift restrictions at all. However, that’s not realistic.

Public health officials in Canada say they are preparing for life with fluctuating levels of the virus for several years to come. A second wave of the virus this fall is of particular concern. 

“This virus is going to be with us for some time. It will not be eradicated from the world in months,” Canada’s chief public health officer Dr. Theresa Tam said back in March. “We will need to be prepared for another wave, potentially.”

That means designing the lifting of public health orders and restrictions in such a way that they can quickly be reimplemented if cases spike again. Contact tracing and testing will be key to fending off a second wave as well as being able to identify new cases quickly and isolate them.

Tam says we need to test more people for that to happen. Canada is aiming to test 60,000 people per day, including anyone with symptoms and asymptomatic people in high-risk environments. This week, Canada is testing an average of 26,000 per day, so we’re not quite half-way there.

People wait in line at a COVID-19 walk-in test clinic in Montreal North on May 10, 2020.

“That’s one of the things we are working very hard to have in place, the surveillance that we need, the testing that we need, the contact tracing in our community that we need,” Henry said.

Alberta’s already started offering tests to asymptomatic people in Calgary, which has been particularly hard-hit by the virus. 

“The success of our testing program is that we can respond to demand, we can respond to surges and that’s what we’re making sure we have put in place,” Alberta chief medical officer Dr. Deena Hinshaw said last week.

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