TORONTO -- From the start of the pandemic, scientists believed people could transmit COVID-19 to other people for up to 14 days.

Now, the latest science suggests that individuals may be infectious for less time -- one reason why the U.S. is cutting its quarantine from two weeks to seven to 10 days.

"I think this is a smart move and it will help us,” Dr. Michael Osterholm, a member of U.S. president-elect Joe Biden’s COVID-19 advisory board, told CNN this week.

The Centers for Disease Control and Prevention (CDC) recommended Wednesday that individuals could quarantine for as few as seven days if they got another COVID-19 test and tested negative within those seven days, and could end their quarantine at 10 days if they did not get tested a second time.

Switzerland and Germany have already reduced their mandatory quarantines to 10 days. Iceland requires five days in isolation with a test to confirm the person is negative for COVID-19. The U.K. is moving to a similar quarantine protocol on December 15.

For now, Canada is maintaining its 14-day quarantine. But new studies like one conducted in Ontario this fall are raising questions about the necessary length of isolation.

More than 10,000 travellers arriving at Toronto’s Pearson International Airport volunteered to participate in a study where they were tested at the airport on arrival, and then performed self-tests with a home kit seven days into their quarantine and at 14 days. These tests were couriered to a lab at McMaster University, where they were processed using PCR tests like those performed by public health labs.

Interim results showed that 95 per cent of COVID-19 positive cases were picked up within the first seven days.

And although those who tested positive at 14 days could’ve caught COVID-19 on the plane and presented late, researchers pointed out that they could also have broken quarantine and become infected in the community.

“They can't go out, they can't do a lot of other things, so it's a certain amount of hardship for people to stay in quarantine for 14 days,” Dr. Marek Smieja, scientific director at McMaster HealthLabs, told CTV News.

“We also know that there are significant economic, social and psychological costs from having to be in the quarantine,” said Dr. Vivek Goel with the University of Toronto and is Aldo with the McMaster research group

“So, any way that we can start to lift the quarantine requirements will help in restoring travel.”

Graham Wright and his wife Janet Whylie are in quarantine for two weeks after returning from Florida, and are among those in Canada who would welcome a shorter quarantine period.

“I feel that seven days is enough,” Graham told CTV News. “My main concern with [the] 14-day quarantine period is that I don't believe people will follow through with it.”

Ontario Premier Doug Ford said Wednesday that he was pushing to “knock down” the quarantine time from 14 days to a shorter period. He added that he was working with the federal government on replacing the quarantine with a project that would use rapid tests as travellers arrived in Canada, similar to a pilot project being run in Alberta.

As of right now, the overarching guidelines for Canada regarding entrance into the country have not changed, with the 14-day quarantine still required. No plans have been announced by Health Canada to change it.