BEIJING >> Australia and Canada have joined a growing list of countries requiring travelers from China to take a COVID-19 test prior to boarding their flight, as China battles a nationwide outbreak of the coronavirus after abruptly easing restrictions that were in place for much of the pandemic.

Australian health authorities said Sunday that from Jan 5. all air travelers from mainland China, Hong Kong or Macao will need to show a negative COVID-19 test taken within two days of their departure.

Canadian authorities announced similar measures that will also come into effect Jan. 5 in a statement dated Saturday — a move experts say isn’t very effective.

Kerry Bowman, assistant professor at the University of Toronto’s Temerty Faculty of Medicine, said the requirement is “not based on science at this point.”

“This isn’t the early days of the pandemic,” he said. “It’s pretty clear that point-of-entry screening is not very effective at all. Often people can test positive days and weeks later.”

Dr. Isaac Bogoch, associate professor at University of Toronto’s Temerty Faculty of Medicine, said it’s not entirely clear what the policy’s goals are, but such measures have not helped.

“We know from the past that very focused and targeted travel measures such as this don’t do much to prevent the spread of COVID, either by importing COVID to Canada, or by the threat of variants of concern in Canada,” he said.

Australia and Canada join other countries including the U.S., U.K., India, Japan and several European nations in imposing tougher COVID-19 measures on Chinese travelers amid concerns over a lack of data on infections in China and fears of the possibility that new variants may spread.

Research has shown how the virus spreads through human mobility, which means that the next variant of the virus may not even emerge from China, and even if it did, it could land in Canada from other indirect routes, Bowman said, adding that a more effective measure would be testing wastewater from airplanes and airports to check for the viral load and mutations.

Vancouver International Airport said Saturday it would expand its wastewater testing pilot program.

China, which for most of the pandemic adopted a “zero-COVID” strategy that imposed harsh restrictions aimed at stamping out the virus, abruptly eased those measures in December. Chinese authorities previously said that from Jan. 8, overseas travelers would no longer need to quarantine upon arriving in China, paving the way for Chinese residents to travel.

Hong Kong is also preparing for quarantine-free travel to China, with plans to resume operations of more border checkpoints as early as Jan. 8, according to a Facebook post by Hong Kong Chief Secretary Eric Chan.

However, a quota will remain in place limiting the number of travelers between the two places.

“Depending on the first phase of the situation, we will gradually expand the scale for a complete reopening of the border,” Chan said.

In China, eased restrictions meant that residents could celebrate New Year’s in large-scale gatherings that were prohibited for much of the pandemic, even though the country is experiencing a massive outbreak of cases.

“There are still some worries, more or less,” said Wu Yanxia, a 51-year-old Beijing resident who works at a logistic company. “I hope that next year everything will be normal, such as domestic travel.”

Others hope that 2023 will bring better things after a difficult past year.

“We have experienced a very uneven year, particularly unforgettable, with many things out of our imagination,” said Li Feng, a teacher in Beijing, adding that 2022 was a difficult year for both the people and the government.

“But I think we have come through and everything will be fine,” Li said. “All of us will be better, and better in both work and life.”