Canada 'sort of flying blind’: Stopping COVID-19 travel PCR tests will put country at risk, experts say

Jennifer Eriksson sanitizes her hands before she is tested as passengers arrive at Toronto's Pearson airport after mandatory coronavirus disease (COVID-19) testing took effect for international arrivals in Mississauga, Ontario, Canada February 1, 2021. REUTERS/Carlos Osorio (Carlos Osorio / reuters)

While some fully vaccinated Canadian travellers may not be thrilled about having to provide proof of a negative COVID-19 test when returning from travel, particularly from the U.S., some experts are warning that it is still an important part of our COVID-19 management and surveillance strategy.

“Testing is a really important part of how we keep track of what's happening with this virus and what's happening in the pandemic,” Julianne Piper, research fellow and project coordinator with the Faculty of Health Sciences at Simon Fraser University told Yahoo Canada. Piper is also a member of the Pandemic and Borders Research Group.

It's prudent, maybe not popular, for the Canadian government to keep that mandatory 72 hour negative test result as a caveat to being able to travel in Canada.Julianne Piper, project coordinator, Faculty of Health Sciences, Simon Fraser University

“The fact that even fully vaccinated travellers are at risk of becoming ill or of transmitting the disease, is still absolutely not risk-free and and testing is one of the strongest mechanisms that we have, or most effective mechanisms we have, to be able to catch those cases, to identify them and to hopefully take actions to prevent those cases from having a wider impact in the community.”

She added that without a testing measure in place Canada is “sort of flying blind."

“The reason testing is valuable is's basically all the epidemiological data that we have on what's happening with the virus, “ Piper said. “So if you're not testing people as they come in, then you don't have a clear idea of what variants are causing problems, whether there's potentially a new emergent variant.”

“That testing piece is still really important and I imagine it will be for some time.”

Piper explained that testing done in Canada on arrival, currently only being done with a randomized sample of fully vaccinated travellers, is "critical to surveillance" of COVID-19 within Canada, while the pre-departure testing is aimed to prevent individuals who have COVID-19 from travelling and "contributing to onward spread of the disease."

While Dr. Stephen Hoption Cann, epidemiologist and clinical professor with school of population and public health at the University of British Columbia, also warned that fully vaccinated travellers are still able to pick up COVID-19, he does not believe that this pre-arrival testing will “catch” many cases, including individuals travelling to the U.S., but there are still concerns about the identification of new variants of concern that emerge globally.

“It's probably not going to catch very many cases, it probably won't have a huge impact,” he said. “But there is some impact there."

"There's always the concern with the spread of new variants, like we've seen the Delta plus variant now spreading in the U.K. and it’s seen in the U.S. and some other countries, so there's always that concern of the the unknown infectious variants that are spreading.”

'It's not no risk, even though you're fully vaccinated'

From a public health perspective, Piper stressed that we’re not “fully out of the woods yet” with COVID-19 but there are a number of different “policy trade-offs” in terms of weighing the economic and social impacts of various travel measures.

“I'm not so surprised to see the loosening of these restrictions, particularly given the vaccination rates that we have the privilege of enjoying in Canada and the U.S.,” Piper said.

“I think it's the right move to limit the loosening of these restrictions to fully vaccinated travellers, we know that this group of travellers will pose the least risk.”

When individuals are considering their travel plans, Hoption Cann believes being aware of the COVID-19 situation in the particular location you are travelling to is important.

“I think that's a very important consideration, to look at what the levels of infection are in the areas you're traveling to,” he said. “Even if you're fully vaccinated, if you're elderly or you have some compromised immune system, you're still potentially at a high risk of developing a more severe infection.”

It's not no-risk, even though you're fully vaccinated.Dr. Stephen Hoption Cann, epidemiologist

Piper explained that travellers should not only look at what is happening in terms of COVID-19 transmission and outbreaks where they’re travelling to, and from, but also keep in mind that COVID-19 responses are different globally, and even within different countries as well.

“What our research has shown and what you can see is that countries have responded very differently, in different ways, at different times, with changing measures to restrict or require different steps to be taken by travellers,” she explained.

“It's not necessarily about a single measure, not necessarily just about if you're only letting fully vaccinated travellers come in or out, but also the place for public health reasons within a jurisdiction, like social distancing, like vaccine passports to go into restaurants, that will affect how the virus is transmitting in a certain area.”

A sign for the coronavirus disease (COVID-19) test collection centre is seen at Vancouver International Airport in Richmond, British Columbia, Canada February 22, 2021. REUTERS/Jennifer Gauthier
A sign for the coronavirus disease (COVID-19) test collection centre is seen at Vancouver International Airport in Richmond, British Columbia, Canada February 22, 2021. REUTERS/Jennifer Gauthier

'We don't know fully how long that immune response lasts'

Hoption Cann said one important element that needs to be determined is how long immunity lasts after you are fully vaccinated, which impacts how long the measures we have in place today will have to remain.

“We do see antibodies declining over time but that's to be expected,... still we don't know fully how long that immune response lasts, is it a year, several years, a lifetime,” he explained.

“Then there are those variants coming out, which, so far, we've been pretty lucky that the variants that we've seen, that are of concern, we're still seeing protection from our vaccines against these variants. That may mean we need to get vaccinated every year, so it's still not clear, at this point, how that process is going to work out in the long term.”

Hoption Cann added that this is a particularly important consideration when we look to countries around the world that don’t have the same access to vaccines that we see in Canada.

“That's an important component and also really looking at developing countries, and getting individuals in those developing countries vaccinated, because there's so much international travel,” he said. “It's really important to get the rest of the world vaccinated, and developing programs to do that.”

Piper stressed that while Canadians are accessing COVID-19 vaccines, it’s still going to be “quite some time” until vaccines will be fully available and accessible globally.

As long as there's transmission happening in certain parts of the world, there's a chance that a new variant of concern may emerge and, worst case scenario, that variant of concern would be vaccine evasive or still able to sort of transmit at high levels in fully vaccinated populations.Julianne Piper, project coordinator, Faculty of Health Sciences, Simon Fraser University

Hoption Cann ultimately has one very important message, whether you’re planning on travelling to the other side of the world or staying more local - get fully vaccinated.

“There's quite a lot of safety data now collected on these vaccines, we know they're safe, we know they're effective,” he said. “So if you're not vaccinated or not fully vaccinated, you should get vaccinated because the safety data is there, they're safe and they're effective.”