Travelers wait for a shuttle bus to a government-designated hotel at Toronto International Airport in Mississauga, Ontario, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Zou Zheng/Xinhua)

A medical worker shows a COVID-19 At-Home Specimen Collection kit at Toronto International Airport in Mississauga, Ontario, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Zou Zheng/Xinhua)

Travelers wearing face masks leave the arrivals hall of Vancouver International Airport in Richmond, British Columbia, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Liang Sen/Xinhua)

Medical workers wearing protective gear work at a COVID-19 testing site at Toronto International Airport in Mississauga, Ontario, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Zou Zheng/Xinhua)

An airport staff member with a face mask and a shield is seen at the arrivals hall of Vancouver International Airport in Richmond, British Columbia, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Liang Sen/Xinhua)

A worker with face masks sanitizes the arrivals hall of Vancouver International Airport in Richmond, British Columbia, Canada, on Feb. 22, 2021. Starting from Monday, travelers arriving in Canada by air are required to take a COVID-19 molecular test before they exit the airport. They are also required to quarantine for three days at a government-designated hotel at their own expense until they get a result. (Photo by Liang Sen/Xinhua)