While the Canadian government has implemented strong measures to ensure fully vaccinated foreign travellers coming into Canada won't be a significant source of COVID-19 spread, the protections implemented will certainly not eliminate the risk, medical experts say.
"Certainly the optics aren't ideal, as we are in a fourth wave and cases continue to climb across the country," said Dr. Isaac Bogoch, an infectious disease specialist and member of Ontario's COVID-19 vaccine task force.
Under the measures, travellers must be fully vaccinated with a Canadian-approved vaccine at least 14 days prior to arriving and have received a negative COVID-19 test within 72 hours of their scheduled flight or their arrival at a land border crossing — requirements that, while not perfect, are "very very good" at ensuring people coming don't have COVID-19, Bogoch said.
"It's not full proof, it's not a hermetically sealed border, we'll still have cases of COVID introduced. It's just going to be fewer than if we had no protection whatsoever," he said.
On Tuesday, Canada opened its borders to fully vaccinated non-essential foreign travellers from across the globe, allowing them to skip the 14-day quarantine requirement. Canada is currently in the midst of a fourth wave of COVID-19 fuelled by the delta variant. However, most of the country's cases and hospitalizations are among the unvaccinated.
Low test positivity rate at border
According to the Canada Border Services Agency (CBSA), the volume of travellers has increased in recent months, but the border test positivity rate for COVID-19 has remained low. For example, between Aug. 9 and 26, the positivity rate for fully vaccinated travellers randomly selected for testing at border crossings was 0.19 per cent (112 positive tests out of 58,878 completed), the CBSA said.
Still, Dr. Donald Vinh, an infectious diseases expert at the Research Institute of the McGill University Health Centre in Montreal, expressed concern that the federal government formulated the open border policy for foreign travellers back in early July, when the delta variant wasn't as much of an issue in Canada.
Vinh said that plan was based on the assumption that those fully vaccinated were not only protected from infection but would not be a major source of transmission. Instead, the delta variant has shown that fully vaccinated people can still be infected and still transmit the virus, he said.
Meanwhile, the full rate of breakthrough cases — those in which a person has been infected despite being fully vaccinated — is still unknown, he said.
"If we had no or low rates of community transmission right now, you could argue that our perhaps more relaxed approach could be acceptable," Vinh said. "We already have high, high, high rates of transmission across the country. So now what we don't want to do is be literally adding fuel to the fire."
The government has introduced special requirements for travellers arriving from India or Morocco. Due to a recent surge in COVID-19 cases, all direct passenger flights from India have been suspended until Sept. 21 and from Morocco until Sept. 29. Currently, air passengers from those countries can only enter Canada if they show proof of a negative test taken in a different country and depart from that country to come to Canada.
'Viruses do cross borders'
Dr. Marek Smieja, scientific director of McMaster HealthLabs and a professor of pathology and molecular medicine at McMaster University in Hamilton, suggested there should be some concern about the potential of imported variants. He noted that the alpha and delta variants were both imported into Canada from abroad.
"Viruses do cross borders. And the question is: What's the most prudent way of allowing a reasonable amount of travel?" he said. "There's no doubt there will be new variants."
But the best protection is to eliminate the domestic cases, so if the local COVID-19 levels are very low, health officials will recognize new variants coming in, he said.
"The way you pay attention to imported diseases to get rid of local disease," Smieja said. "I would love to get to the point with COVID where the only cases you see are imported outbreaks."
The federal government's measures, in terms of what's practical, are a "pretty reasonable reassurance" that foreign travellers will be a very low risk, he said.
In terms of potential exposure to COVID, a foreign traveller who's fully vaccinated and tested coming into Canada is likely safer than those many people encounter on a daily basis, Smieja said.
Neighbour poses higher risk
"I would argue that the neighbour in the supermarket who isn't wearing their mask properly above their nose and actually hasn't been vaccinated is a higher risk than the person crossing a border," Smieja said. "I actually think it is a prudent thing to be making it easier for people to travel, particularly for those who are fully vaccinated."
Dr. Zain Chagla, an infectious diseases physician at St. Joseph's Healthcare Hamilton and an associate professor at McMaster University, agreed that it's more important to focus on the pandemic's domestic situation.
With foreign travellers, he said, there's always going to be a risk, and some breakthrough cases, but the government has come up with a good compromise.
"The bottom line is we are going to have to do this at some point in time, and there will be another variant. The world is not completely immunized by any means," Chagla said.
"We're taking a calculated risk, we're following data … to see that, yes, no cases are being generated in Canada or not very many are being generated in Canada as a result of this [foreign traveller policy]."
ABOUT THE AUTHOR
Mark Gollom is a Toronto-based reporter with CBC News. He covers Canadian and U.S. politics and current affairs.
With files from Sophia Harris
Credit belongs to : www.cbc.ca