OTTAWA -- An opportunity to test a potential COVID-19 vaccine in Canadian clinical trials is now "over" because Chinese customs did not approve it for shipment to Canada, according to the National Research Council (NRC).

The NRC confirmed to CTV News on Thursday that CanSino Biologics "does not have the authority" from the Chinese government to ship the Ad5-nCoV vaccine candidate "at this time."

"Due to the delay in the shipment of the vaccine doses to Canada it is evident this specific opportunity is over and the NRC is focusing its team and facilities on other partners and COVID-19 priorities," reads the emailed statement from the NRC.

Headquartered in Tianjin, China, CanSino signed an agreement with the NRC in May. After Health Canada's review and approval, the Canadian Center for Vaccinology was preparing to start clinical trials as early as June, but progress came to a standstill after Canadian authorities said the Chinese government was stalling the shipment process.

"The agreement between the NRC and CanSino was reviewed prior to signature by CanSino’s collaborators in the Chinese Government – the Beijing Institute of Technology and the Ministry of Science and Technology – who had provided funding to CanSino," the statement says.

"Subsequent to signing, the Government of China introduced process changes regarding shipping vaccines to other countries. The process is not clear to the NRC."

CanSino Biologics did not respond to’s request for comment at the time this story was published.

The Ad5-nCoV vaccine candidate has already been sent to other countries including Russia, Chile, Argentina, Pakistan and Saudi Arabia for Phase 3 trials or large-scale testing on humans.

Human trials of the vaccine candidate are also in Phase 3 in China, with results promising enough that the Chinese government has approved it for use in its military. The vaccine was one of the first in the world to enter the second phase of human clinical trials after it presented no major safety issues.

Normally, testing a vaccine can take five to seven years, but the anticipated Canadian clinical trials were expected to be fast-tracked through typical regulatory hurdles due to the urgency of the pandemic.

CanSino's vaccine was developed using a cell line from the NRC that was previously used to produce an Ebola vaccine. The two organizations have worked together since 2013.

Meanwhile, Canada's Foreign Affairs Minister Francois-Philippe Champagne downplayed suggestions that the vaccine partnership failed because of ongoing political tensions between Canada and China.

"I don't necessarily think so," Champagne told reporters Thursday. "I can only speak for the Canadian side. I would not necessarily link whether that particular opportunity is linked to anything else."

Relations have been tense since the Chinese detained Canadians Michael Kovrig and Michael Spavor in apparent retaliation for the RCMP's arrest of Chinese tech executive Meng Wanzhou on an American extradition warrant in December 2018.

Dr. Scott Halperin, director of the Canadian Centre for Vaccinology, added that losing access to the vaccine may set Canada back in the fight against COVID-19.

"The CanSino vaccine is one of the most furthest along of any of the candidate vaccines so it would have been nice to do that study," Halperin said. "It's not the only vaccine that we are working with ... but we certainly don't like to lose access to any one of them because we need multiple vaccines."

He notes that had his lab received the vaccine its study would have been "well along by now."

"We thought the shipment would be coming any day, as did the company," he said. "There was no bad faith on the company -- they were trying everything but they could not get (Chinese) government approval to ship it. The request for shipment hasn't been denied it just hasn't been approved."

Clinical pharmacologist Sabina Vohra-Miller says handing over that kind of asset without securing intellectual property rights on the vaccine was a major missed opportunity for Canada.

"This is a miss because you wouldn’t have that by-product if you didn’t have that foundational system of the cell line," she told CTV

"We’re trying to be the noblest citizens in terms of advancing science and making sure that there is no gatekeeping with that, and you would expect that there would be a reciprocity on that."

On Wednesday, Prime Minister Justin Trudeau told reporters several contracts are in the works to ensure Canada gets early access to potential COVID-19 vaccines.

"We’ve actually signed a number of deals with potential vaccine producers around the world. The issue is nobody yet has a vaccine and nobody knows who’s going to develop the vaccine so like many, many countries around the world, we’re working with a range of partners to ensure that when someone does find a vaccine Canadians will have access to it."

The Canadian government also announced in May that it was planning a $44-million upgrade to a NRC facility in Montreal to prepare for the possibility of a large-scale Ad5-nCoV manufacturing effort should human trials be successful.

While multiple trials around the world are progressing, there is currently no accepted cure or vaccine for the novel coronavirus.

With files from’s Solarina Ho and the Canadian Press