TORONTO -- As COVID-19 spreads across the world, causing shutdowns, economic strife and widespread fear, many are looking back at how Canada handled a similar crisis: waves of polio outbreaks that peaked in the mid-20th century.

Although polio is significantly different from the novel coronavirus, some of the similarities between the two outbreaks, especially when looking at the height of the polio issue in Canada, are striking.

Polio was thought to only affect a specific age group at first, but then spread to infect patients of all ages.

Provincial governments tried to quarantine the sick and restrict the movement of those at risk.

The majority of polio cases were mild, but then as time went on, more severe cases began to rack up, causing mass hospitalizations and thousands of deaths.

And some of those who were severely ill needed machines to help them breathe: the dreaded “iron lung.”

WHAT IS POLIO?

Poliomyelitis is an infectious disease caused by a virus, and used to be known as “infantile paralysis” because it largely affected children under five.

Christopher Rutty, an adjunct professor at the University of Toronto and a professional medical historian, said it came from a gastrointestinal virus, transferred through the ingestion of infected fecal matter, which, in most cases caused “a mild upset stomach.”

When the virus got into the nervous system, it became dangerous. Depending on the severity of the illness, polio can permanently damage the nerve cells controlling muscles, causing weakness in some limbs, or even paralysis.

To put it in the words of Canadian musician Joni Mitchell, who contracted the virus when she was nine and described it in a 2000 interview with Inside Connection, “polio is the disease that eats muscles.

"If it eats the muscle of your heart, it kills you; if it eats the muscles that control the flexing of your lungs, you end up in an iron lung; if it eats the muscle of your leg, it withers, or of your arm, it withers.”

Canada has been officially polio free since 1994, but there still is no way to cure polio. The virus can only be prevented.

HOW POLIO ATTACKED CANADA

Polio had been around for a long time before it became a crisis in North America -- outbreaks were recorded in Europe in the early 1800s.

The first Canadian case of polio was in 1910, but it didn’t capture national attention until much later. Waves of polio outbreaks would happen largely in the summer and fall.

For Canada, the worst occurred between 1927 and 1953, as multiple waves buffeted the nation.

The second-worst year of polio for Canada was 1937. Nationally, there were nearly 4,000 cases of the virus -- and around 2,500 of those were in Ontario alone. Toronto newspapers at the time detailed how numerous schools were shut down amid a province-wide public health panic.

The late 1940s and early 1950s saw a stronger wave of outbreaks, putting a heavier strain on the health care system in Canada. At the peak of the polio epidemic in Canada, in 1953, there were nearly 9,000 cases and 500 deaths from coast to coast.

The Royal Canadian Air Force was enlisted to help deliver iron lungs around the country as more and more patients started to develop the most extreme type of polio: bulbar polio.

BREATHING WITH A MACHINE

Before there was the modern day ventilator, there was the iron lung.

Bulbar polio was what happened when the virus reached the brain stem’s motor nerves. It and other forms of polio that attacked chest or throat muscles interfered with the body’s ability to physically breathe. The iron lung helped patients too weak to breathe on their own.

At the start of Ontario’s worst polio epidemic, in 1937, there was only one iron lung in the entire province.

Rutty said there was a “scramble to find materials,” and get machines built.

In one of the most dramatic stories to come out of the polio epidemic in Ontario, 27 iron lungs were manufactured in the basement of what was then Toronto’s SickKids Hospital, before being distributed to the areas of the country most in need.

The ventilators currently being used to help patients with severe COVID-19 work by inserting a tube down the throat to force air into the lungs, bypassing inflammations in the air-passage caused by the virus.

An iron lung is almost the exact inverse -- all outside of the body. A patient’s head sticks out of the machine, while the entire body is encased in what looks like a giant metal coffin. A collar around the neck makes sure there is an airtight seal, and the machine works by using negative pressure to expand and contract a person’s chest.

“A bellow forces air in and out, creates a vacuum, essentially,” Rutty explained to CTVNews.ca in a phone interview. “It forces you to breathe.”

By the ‘50s, iron lungs were more standardized than the emergency SickKids ones, but the demand had risen.

“There were shortages,” Rutty said. “One hospital in Winnipeg had more than … 90 iron lungs running at once.”

What was clear was that iron lungs alone would not solve the crisis. A vaccine was needed.

THE FIGHT TO TREAT THE VIRUS

One of the problems in treating polio was a lack of understanding of the virus itself. Researchers tried to study the disease with monkeys, but it didn’t yield many answers.

“There was a lot of mystery around it for a long time,” Rutty said. “It's a virus. It's a human-only virus, and viruses are problematic to deal with.”

In the fight to treat polio, many treatments were talked up before there was solid evidence that they actually worked. Starting in 1927, provinces stockpiled a convalescent serum made from spinal fluid despite little evidence that it worked as treatment or prevention.

After a prophylactic nasal spray was tested out in the U.S. -- with no clear results -- public pressure surged in Canada to test it here.

During Ontario’s 1937 outbreak, they performed a much-hyped clinical trial of the spray on 5,000 children. However, the spray did nothing to prevent the virus, and also left many of the children without a sense of smell.

According to excerpts from the London Free Press at the time, panic-stricken parents were demanding sprays from their doctors outside of the experiment, or even manufacturing their own, reflecting a desperation for treatment that we’ve seen today with COVID-19. Some have put themselves in hospital or died trying to obtain treatments that have yet to be tested properly, such as an Arizona couple who in March took a form of chloroquine used in aquariums -- chloroquine phosphate -- after U.S. President Donald Trump touted the pharmaceutical version of the drug as a treatment for COVID-19.

Studies are currently underway to investigate whether drugs such as chloroquine and remdesivir could be used to treat COVID-19, but there isn’t enough data yet to say for sure.

In 1935, two early attempts at polio vaccines used in the U.S. only served in increase the tragedy there, as they were based on an inaccurate understanding of the virus.

But when a viable vaccine was finally developed, Canadian researchers were instrumental in producing a version that could be tested in humans.

Jonas Salk, an American scientist, is known as the creator of the first polio vaccine to be tested in humans. But his inactivated vaccine, which “seemed to work in monkeys,” Rutty said, wasn’t ready for human trials until a collaboration with Connaught Medical Research Laboratories, part of the University of Toronto.

Researchers there had created “the first purely synthetic tissue culture media” in 1949, Rutty said. It was a nutrient-base mixture of 60 ingredients, and was non-allergenic because it didn’t use serum from any animals.

It was called “Medium 199,” and it solved all of Salk’s problems, because it could serve as a safe medium for the vaccine.

“(It) actually opened the door for human testing of polio vaccine,” Rutty said.

The next problem? Producing the vaccine on a mass scale for human trials.

Connaught pioneered the “Toronto Method,” in 1952-53, which allowed researchers to create large quantities of poliovirus in rectangular bottles filled with Medium 199. At the request of the National Foundation for Infantile Paralysis, an American foundation started by Franklin D. Roosevelt, Connaught shipped as many bottles of Medium 199 with polio as possible for a massive field test in the U.S.

The 1954 trial involved more than 1.8 million children. On April 12, 1955, Salk’s vaccine was declared a success, only a couple weeks after the Canadian trial of the Connaught vaccine had been started.

But tragedy struck not long after.

Suddenly, 79 American children who had been given the vaccine contracted paralytic polio.

“And the whole U.S. … vaccine rollout stopped,” Rutty said.

It was discovered later that due to a lack of properly batch-testing the vaccine, one company in the U.S. had produced vaccines that weren’t properly inactivated.

Canada was suddenly faced with a dilemma: Should we also stop vaccine testing?

Then-Prime Minister Louis St. Laurent wanted to cancel the program due to pressure from the public.

But Paul Martin Sr., Canada’s Minister of National Health and Welfare at the time, had confidence in Connaught. He also had a vested interest in battling polio -- he had become Health Minister just after his son, Paul Martin Jr., who would later go on to become prime minister, contracted polio in 1946.

Martin Sr., who also had polio as a child in 1907, argued the Canadian trial should continue.

His decision “saved the vaccine,” Rutty said.

The Canadian rollout of the vaccine was successful, and spoke to the strength of the Canadian health-care system.

It also showed confidence in the Salk vaccine, which allowed for it to be implemented internationally elsewhere, vaccinating millions before an oral vaccine was produced by Albert Bruce Sabin in the 1960s to replace it. Connaught was also involved in trials of the Sabin vaccine.

VIRUS REVEALS INEQUALITIES

Polio, like COVID-19, demanded attention from governments in a way many other deadly diseases hadn’t before, simply because of who was most at risk.

The virus affected predominantly middle-class children. It had been circulating long before the outbreaks in North America, Rutty explained, and lower-income families who had been exposed to mild forms of it earlier due to poorer living conditions had more antibodies built up over generations. So it was the middle-class who had no group immunity when outbreaks started popping up.

COVID-19 affects all groups, and those living in poverty are often more likely to be on the front lines and more at risk.

But the first cases coming to Canada were largely those who were wealthy enough to travel internationally for vacations or cruises -- and these victims captured media and government attention from the start, long before the virus hit the general population.

And as COVID-19 is spurring discussions about how to economically support Canadians during a health-care crisis, polio was responsible for a similar restructuring.

“It was a very politically potent disease in that sense that it wasn't just something that came and went,” Rutty said. “It was a potentially lifelong legacy of having polio for many people. And private health insurance had its limits.”

Although universal health care would not be implemented until 1984, the polio epidemics shifted the thinking of Canadian officials, Rutty said.

There were new financial programs introduced to help families support loved ones who were stricken with polio. Martin Sr. also introduced a new federal health grants program in 1948, which helped provinces improve health services, an important step on the way to a more comprehensive health care plan.

Rutty said that these types of crises can expose issues that already existed.

“That’s really where the threat of COVID is, it’s striking at the health care system and really exposing limitations in it,” he said. “And polio did the same thing, really, because of its long-term impacts.”

As we move forward in the battle against COVID-19, Rutty said it’s possible to learn from what we did right in the fight against polio, both scientifically and politically.

He pointed out that “COVID is generating similar kinds of collaborative initiatives, research and production,” in terms of scientists collaborating in the search for treatment and a vaccine, “which really hasn't happened quite the same way really, perhaps even since polio.”

The difference between how Canada and the U.S. are handling COVID-19 also harkens back to the days of polio, he said.

“I think that … differentiations between governments and between how the U.S. and Canada dealt with polio is kind of similar in many ways to what's happening now with COVID,” Rutty said. “We're seeing quite a disjointed and confused situation in the States.

“COVID is generating an unprecedented kind of government response (in Canada), public health wise and economically … which was kind of like polio,” he added. “Closer to polio than probably anything else, actually.”