WATCH: Trudeau transport minister again struggles to justify vaccine mandates in Canadian travel

Transportation Minister Omar Alghabra told reporters on Thursday that masks continue to "reduce odds of transmission," though he could not say how it was possible that Ontario is set to drop mask mandates in hospitals.

Alghabra was asked why it was fair that unvaccinated Canadians could not see their families across the country due to his government's policies, to which he said that the "same applies to vaccine mandates."

"These measures are always getting assessed and reassessed," he said.

Alghabra appeared to have some difficulty answering exactly why the mandates are still in place when no other jurisdiction in Canada has vaccine mandates for the regular person.

He could not answer what the technical justification is for mandates.

The mandate, which has been in place since November 2021 to boost vaccination rates" and "prevents unvaccinated Canadians from boarding a commercial plane or train in Canada to both domestic and international destinations."

Last week, Alghabra appeared on CBCs Power & Politics, where he again had difficulty rationalizing Trudeau vaccine mandate.

Host Vassy Kapelos asked Alghabra what the government's justification for keeping domestic vaccine passports in place was, to which he said, "Vassy, it's all guided by our desire to protect the health and safety of Canadians. Obviously, these measures will always be reassessed and assessed, and we're constantly having discussions with our experts about when is it the right time to adjust this measure or that measure.

"The same applies to domestic travel. These measures are being done to protect the health and safety of Canadians. Just like mask-wearing, as well, on airplanes, on trains. These are done to protect the health and safety of Canadians," he continued.

"There will be a time when these measures are adjusted or lifted, but we want to always err on the side of safety... I think Canadians expect a responsible government to do so."

Health experts as of late have been pointing out that Canada's domestic vaccine mandate holds up to very little scrutiny.

Zain Chagla, an infectious diseases physician and an associate professor at McMaster University, wrote in The Globe and Mail three weeks ago that the logic behind vaccine mandates for travellers "no longer holds."

Chagla wrote: "We need to bring down the other limits to individual rights that don’t make medical sense. This is why we should reconsider our mandate requiring full vaccination for Canadians boarding a commercial plane or train for travel to domestic and international destinations."

Chagla argues that vaccine mandates were put in place to help prevent transmission, but as of the Omicron variant, that doesn't appear to be the case any longer.

"The efficacy of a prior infection against reinfection approaches that of two doses of vaccines; since many unvaccinated individuals have likely been infected, they may now have a similar level of immunity to their vaccinated peers. Additionally, since Canadians under the age of 12 are not currently required to be vaccinated, unvaccinated individuals have effectively been a part of travel all along – meaning that environments of exclusively vaccinated individuals do not exist."

But health experts aren't the only ones sounding the alarms over the ineffective passport.

Just one day after Alghabra's disaster interview on CBC, Liberal MP Nate Erskine-Smith wrote in a Twitter thread that he believed the mandate has exhausted its usefulness.

"I didn’t support the idea of dropping masks right away, but I’ve also made it clear to the government that a two-dose vaccine mandate without accommodation is no longer justified," Erskine-Smith wrote in a Twitter thread after a failed Conservative Party motion that would have seen Canada go back to pre-pandemic levels of regulation.

"We first debated these questions at the end of February. At that time, Dr. Tam had indicated that a review of mandates was warranted. As I noted in my reasons then, an immediate and transparent re-evaluation should have taken place at that time," he said, but added that the re-evaluation of travel measures has not been transparent.

"Nothing about the re-evaluation of travel-related measures has been transparent. It is not clear what Dr. Tam’s recommendations are, and there’s been no adequate justification provided for continuing the exclusive two-dose mandate," he wrote.

Erskine-Smith said that mandates were put into place to increase vaccination rates and reduce risk of transmission, but that the Liberal government's mandate has exhausted its usefulness.

The Canadian Airports Council on Tuesday called for the removal of "all vaccine requirements for air passengers and aviation employees."

"The aviation community has been a supportive partner of the federal government, in facilitating the vaccine mandate for travel since November 2021," they wrote. "However, today all Canadian provinces have removed vaccine restrictions, so there is now a different standard for aviation employees and transportation than for other Canadians.

"Aviation is global. In order to support this industry's economic recovery and compete globally, Canada must align with the international community and join the list of over 50 countries that have already removed vaccine mandates and COVID protocols for travel," they wrote earlier this week.