In FCA Canada Inc. v Unifor, Locals 195, 444, 1285,[1] the union challenged the reasonableness of the employer’s COVID-19 vaccination mandate (the “Policy”). The main issue before the arbitrator was whether the Policy was reasonable in light of the changing nature of the pandemic. Ultimately, Arbitrator Nairn found the Policy unreasonable in light of COVID-19’s changing nature.

The Policy stipulated that all employees, contractors, suppliers, and visitors had to be fully vaccinated in order to attend the employer’s work sites. These work sites included manufacturing/assembly operations, parts distribution warehouses, business centers, training centers, and offices. To be considered fully vaccinated under the Policy an individual must have received two-doses of the COVID-19 vaccine.

The Policy provided that employees who were not fully vaccinated, or who had not disclosed their vaccination status, would be placed on an unpaid leave of absence and further that employees may be subject to discipline for non-compliance, up to and including termination.

In her decision, Arbitrator Nairn noted that while no employees had been terminated due to non-compliance with the Policy, several had been placed on indefinite unpaid leaves of absence. At the time of the hearing, the employee vaccination rate was 94.6%.

After reviewing the specific context of employment and the scientific evidence regarding vaccination efficacy (and despite acknowledging the continuing dangers associated with COVID-19), Arbitrator Nairn concluded that:

… a COVID-19 vaccine mandate defined as requiring two doses (of a two-dose vaccine) is no longer reasonable based on the evidence supporting the waning efficacy of that vaccination status and the failure to establish that there is any notable difference in the degree of risk of transmission of the virus as between the vaccinated (as defined in the Policy) and the unvaccinated. Rather, the evidence supports a conclusion that there is negligible difference in the risk of transmission in respect of Omicron as between a two-dose vaccine regimen and remaining unvaccinated. There is, under the definition in the Policy, no longer a basis for removing unvaccinated employees from the workplace.

The Arbitrator declared the Policy to be of no force or effect.

It is worth noting that Arbitrator Nairn specifically said that this decision should “in no way be taken as support for remaining unvaccinated absent a legitimate exemption.” Rather, it referred to the particular circumstances of the workplace over the relevant period, in relation to the Policy as written and the available science, any and all of which may change.

A number of subsequent decisions have upheld mandatory vaccination policies, including IAFF, Local 3888 v Toronto (City) (Mandatory Vaccine Policy), Re[2] and Regional Municipality of York v Canadian Union of Public Employees, Local 905 (Long Term Care Unit).[3]

These cases highlight the importance of assessing each situation’s unique factual matrix. The circumstances surrounding the particular workplace and the policy at issue will dictate the need for employers to update their COVID-19 policies to account for the pandemic’s changing landscape.

A summary of other decisions regarding vaccine mandates can be found in our April Communique.


These decisions demonstrate how the legal landscape for mandatory vaccination policies is shifting. Employers should review their existing vaccination policies periodically to determine if revisions are appropriate due to COVID-19’s changing nature.