This column is an opinion by Dr. Vivek Goel. He was the founding head of Public Health Ontario, set up in response to the SARS crisis, and is currently a professor at the University of Toronto's Dalla Lana School of Public Health and vice-president of research, innovation and strategic initiatives at U of T. For more information about CBC's Opinion section, please see the FAQ.

It's wrong for the United States and others to ban visitors from China due to novel coronavirus, just as it was wrong to restrict travel to Toronto in 2003 due to SARS. And Canada should stand firm in the face of any political pressure to reverse its decision to keep our borders open.

When the emergency committee of the World Health Organization (WHO) declared the new coronavirus a "Public Health Emergency of International Concern" on Jan. 31, it also made clear it "does not recommend any travel or trade restriction."

Nonetheless, the United States moved quickly to bar all non-U.S. citizens from entering the country if they had recently traveled to China. At least 20 countries have imposed similar measures, including Australia, New Zealand, India, Israel, the Philippines, Singapore and South Korea.

The moves may be driven by an overabundance of caution, fear, xenophobia, or a mix of these and other factors, but they aren't supported by science or evidence-based public health best practices.

Canada, as well as European and South American countries, are among those that have heeded the advice of the WHO, advice which is based on evidence learned from past experience with outbreaks.

A woman walks past an electronic board showing flight schedules at Incheon International Airport in South Korea, one of the nations that has imposed travel restrictions on people who have been in China recently. (Kim Hong-Ji/Reuters)

After the 2003 SARS outbreak in Ontario, I had the privilege of helping build Public Health Ontario, the agency created to co-ordinate the provision of scientific and technical advice to front-line health professionals, public-health units and the government.

The first big test of the agency came in 2009, with the H1N1 pandemic. Our actions, and those of public-health agencies around the world, helped control this event.

Many public-health measures were put in place, but one clearly had a limited role to play in managing the spread of disease: Travel bans.

Given the speed at which viruses can spread, travel bans are usually too late to contain such outbreaks. Our resources should be invested in public-health control measures that are shown to work, based on evidence.

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With coronavirus, China has already taken unprecedented internal control measures to contain its spread.

Since Jan. 23, Chinese authorities have effectively stopped all travel in and out of the city of Wuhan, epicentre of the outbreak, and the surrounding province of Hubei. As a result, about 50 million people are effectively in quarantine. Those who are authorized to leave, such as the Canadians Ottawa repatriated on a flight from Wuhan overnight, undergo medical assessments prior to departure.

The cases of coronavirus outside of Hubei are predominately connected to people who travelled before China's lockdown. If travel restrictions had been necessary, the time to have used them would have been much more than two weeks ago, given the lifecycle of the virus.

In any case, travel restrictions serve only to slightly slow the spread of outbreaks. They do not protect against outbreaks, as studies of past events have shown.

And they come with a huge economic cost.

In 2003 for example, prior to adoption of the current International Health Regulations, the WHO did advise travellers to avoid Toronto during the SARS outbreak. Then-mayor Mel Lastman may not have known about the WHO — "I don't know who this group is," he told CNN — but he wasn't wrong to criticize the UN health agency's travel advice at the time.

It did little to limit the impact of SARS globally, but it had a massive effect on the economy of Canada, and Toronto in particular, where the tourism industry alone lost an estimated $1.1 billion.

To repair the damage required no less than The Rolling Stones, AC/DC, Rush and Justin Timberblake, for the attendance-record-breaking Toronto Rocks concert to show the city was open for visitors and business again.

Concert-goer Andy Johnston of Atlantic City takes a drink of water as he waits for the bands to begin at a massive concert for SARS relief in Toronto on July 30, 2003. (Jonathan Hayward/Canadian Press)

This time, having learned from previous outbreaks, the WHO has it right with its response to novel coronavirus.

On Feb. 4, the WHO's director-general Tedros Adhanom Ghebreyesus reiterated his call to all countries not to impose restrictions that unnecessarily interfere with international travel. These restrictions can increase fear and stigma, he said, "with little public health benefit."

The Canadian government is on the correct track in heeding this message.