Even for tech companies who create the tools for remote work, returning to the office is proving a major challenge. After early work from home recommendations last March, companies like Google eventually closed up shop, requiring employees to take their work home with them. The intervening year and change have been a fraught balancing act for the company (along with most of the world), which began outlining return to work plans for some employees as early as May 2020.

As Delta and other Covid-19 variants threaten anticipated returns to normalcy, Alphabet CEO Sundar Pichai offered a clearer look at the company’s new normal. In a letter to employees reprinted on the Google Keyword blog, Pichai notes that all employees working out of one of Google’s campuses will need to be vaccinated.

“We’re rolling this policy out in the U.S. in the coming weeks and will expand to other regions in the coming months,” Pichai writes. “The implementation will vary according to local conditions and regulations, and will not apply until vaccines are widely available in your area.”

Further complicating matters is the second bullet point. While the rise of the Delta variant is expanding the company’s work-from-home policy through October 18, it’s not entirely clear what happens after that date (assuming the virus doesn’t force another goal post shift) to unvaccinated employees, who may not be able work out of a Google office or remotely.

The post does, however, note some exception for those unvaccinated for “medical or other protected reasons.” Google hasn’t clarified how it will enforce such exceptions.

“For those of you with special circumstances, we will soon be sharing expanded temporary work options that will allow you to apply to work from home through the end of 2021,” Pichai writes,.“We’re also extending Expanded Carer’s Leave through the end of the year for parents and caregivers.”

Other tech giants like Apple have also pushed back return-to-office plans and implemented masks in retail stores, as mandates have gone into effect amid increasing Covid-19 rates. Others, including Facebook, are sticking with original Fall reopening plans.

“Expert guidelines state that vaccines are highly effective at preventing variants of Covid-19, including the Delta variant,” a spokesperson for the social media giant recently told The Wall Street Journal. “Our timelines to reopen our offices haven’t changed.”