OTTAWA -- As Canada contemplates the use of vaccine passports or certificates, the country’s privacy commissioners are warning that in light of privacy risks, certain conditions must be met before anything is implemented.

In a statement issued Wednesday, the commissioners state that governments and those in the private sector need to consider privacy “at the earliest opportunity” when having the conversation about some sort of COVID-19 vaccine certificate.

“At its essence, a vaccine passport presumes that individuals will be required or requested to disclose personal health information – their vaccine/immunity status – in exchange for goods, services and/or access to certain premises or locations. While this may offer substantial public benefit, it is an encroachment on civil liberties that should be taken only after careful consideration,” it states.

Specifically, they encourage entities to consider the necessity, effectiveness and proportionality of vaccine passports.

They say vaccine passports must be necessary to achieve an intended public health goal and that there are no other less intrusive measures available to reach the same objective. They say vaccine passports must be “likely effective” at achieving their intended purpose, and that privacy risks associated with the passports must be proportionate to the public health goal.

“Vaccine passports must be decommissioned if, at any time, it is determined that they are not a necessary, effective or proportionate response to address their public health purposes,” it states.

The federal government has hinted that some form of vaccine certificate will be issued in order to travel internationally.

Health Minister Patty Hajdu said earlier in the month that she is “working on the idea” with other G7 countries, and that it’s a “live issue.” Transport Minister Omar Alghabra also said he has discussed this with international colleagues and that “a common set of principles” will guide the implementation process.

"At the centre of this effort must be a coordinated approach for testing and a common platform for recognizing the vaccinated status of travellers. As we work to build back better, the establishment of a system that will protect our privacy and personal information, and that will be accessible, fair, and equitable is imperative. We must apply lessons learned from innovative technologies to identify long-term, sustainable solutions and expand upon them globally,” he said on May 5.

In an April report, Dr. Mona Nemer, the chief science adviser of Canada, and a panel of experts reviewed the scientific, ethical, social, and legal considerations and potential uses of vaccine passports or certificates.

They said COVID-19 vaccination certificates present more complexities when compared to other vaccine certificates, such as yellow fever, due to the fact there are multiple available vaccines with varying degrees of efficacy against different variants of the virus.

The privacy commissioners’ statement goes on to note that while they haven’t received any evidence to show the effectiveness of vaccine passports in preventing transmission of the virus, they understand the science is moving quickly and in light of that, as they’re developed, certain privacy principles must be adhered to.

They say private or public entities must have “clear legal authority” when requiring that an individual present a vaccine passport.

“Clear legal authority for vaccine passports may come from a new statute, an existing statute, an amendment to a statute, or a public health order that clearly specifies the legal authority to request or require a vaccine passport, to whom that authority is being given, and the specific circumstances in which that can occur,” the statement reads.

Obtaining consent alone is not sufficient enough for those entities subject to public-sector privacy law, they say, while those in the private sector must follow the “clearest authority,” which would be the newest public health order or law.

Absent an order or law, businesses can rely on consent so long as it’s “voluntary and meaningful” and “based on clear and plain language,” among other conditions.

With a file from CTV News' Jackie Dunham.