Twitter Inc. is among the latest employers enacting a coronavirus vaccination policy for employees.

In an emailed statement to Benefits Canada, the social media company said anyone who wishes to return to its North American offices must be vaccinated and show proof. In May 2020, the company announced it would allow employees to continue working remotely indefinitely or divide their time between home and the office. Twitter — which has roughly 150 Canadian employees, mostly based in the Toronto area — has paused future office reopenings, said the statement.

Read: Twitter to allow employees to work from home ‘forever’

“It’s important that for those staff who choose to return to the office on a permanent or part-time basis, they have confidence they’ll be returning to a safe environment. Once offices in Toronto and elsewhere reopen, it will be the choice of the employee on how they choose to work going forward.”

In addition to Twitter, Shopify Inc. and Sun Life Assurance Co. are also being flexible on where employees work, but both companies said this week that any employees meeting up will need to show proof they’re fully vaccinated. And Sundar Pichai, chief executive officer of Alphabet Inc. and its subsidiary Google, has asked anyone working in its U.S. facilities to be vaccinated, a policy that will be expanded to other regions in the coming months. Meanwhile, Maple Leaf Sports & Entertainment Ltd. and Porter Airlines also announced this week that employees and customers will have to either show proof of vaccination or a negative coronavirus test.

Read: Sun Life allowing staff to choose where they work post-pandemic

At the federal level, Ottawa announced late last week it will require federal employees and workers in federally regulated industries to be vaccinated against the coronavirus. Public servants who can get vaccinated and choose not to will face “consequences'” for their decision if the Liberals are returned to power, Justin Trudeau said Tuesday as the issue of vaccine mandates exploded on the federal election campaign trail. And while out campaigning this week, New Democratic Party of Canada Leader Jagmeet Singh said: “If someone doesn’t get vaccinated in places that we know it would put people at risk, then they would not be able to continue working in those places.”

The Public Service Alliance of Canada, which represents 215,000 federal public service workers, said in a news release Tuesday that the political party leaders have made “concerning statements” about disciplining or terminating workers. “PSAC has been in consultation with the federal government on its vaccination proposal and our position is clear: employees with a valid medical reason for being unvaccinated or for reasons protected by human rights legislation must be offered a formal accommodation under the law.”

Read: Trudeau mandating coronavirus vaccinations for federal employees

Meanwhile, at the provincial level, both the Ontario and Quebec governments are also enacting vaccination policies for workers in certain sectors. Ontario will require employers in health care and education to have policies that ask staff to disclose their vaccination status and require those who are unvaccinated to take an education session and be subject to regular tests.

Dr. Kieran Moore, the province’s chief medical officer of health, said that directive takes effect on Sept. 7, covering hospitals, ambulance services and community and home-care service providers. It will be similar to one already in place in long-term care homes and mirrors policies introduced by some hospitals.

Ontario also plans to introduce vaccination policies in other high-risk settings like children’s treatment centres, congregate group homes, institutional foster homes, post-secondary institutions, retirement homes and women’s shelters.

Read: Employers should weigh human rights, health risks when drafting pandemic policies

In Quebec, health-care workers will need to be fully vaccinated against the coronavirus by Oct. 1. The mandate will apply to any health-care worker who enters into contact with patients for more than 15 minutes at a time, including nurses, doctors and ambulance workers and will apply to both the private sector and public sector, said Health Minister Christian Dubé.

Premier Francois Legault said he hasn’t decided what the penalties will be for those who refuse to be vaccinated, adding that the issue will be part of consultations with opposition parties, which he said could start as early as next week. Other public sector workers such as teachers and bureaucrats aren’t targeted by the vaccine mandate, but Legault said the consultations will also include discussions on whether to extend the vaccination requirement beyond health-care workers.

Read: Employers requiring coronavirus vaccinations must consider human rights, privacy