Back to the office after Labor Day? Not so fast

As COVID surges back, big Boston employers are rethinking their back-to-work plans, and certainly their in-house smoothie bars

Workers at the office of cybersecurity firm Rapid7, near North Station, shortly after it opened in 2019. The company said it is still aiming to bring its 800 local employees back to the office, at least three days per week, in October.David L. Ryan/Globe Staff

For months, the mantra for big employers planning to bring workers back to the office has been “See you in September.” Now, suddenly, it’s becoming “See you in... who knows?”

The swift rise of the Delta variant has some employers rethinking their reopening plans amid rising concern about breakthrough cases and new mask guidance. It’s been the subject of meetings all week, as executives across Boston debate COVID restrictions, vaccine mandates, and in some cases, delayed returns to the office.

The conversation has been building for a month, as new COVID threats emerged. But the feeling that plans might really need to change came on quickly.

Earlier this week the Centers for Disease Control and Prevention recommended fully vaccinated people wear masks indoors in places with “substantial or high transmission,” including Boston. On Thursday, President Biden said federal workers must be vaccinated or test weekly. By Friday, Massachusetts officials were recommending that fully vaccinated people who are at high-risk, or who live with someone who is high-risk or unvaccinated, wear face coverings indoors.

“You know every single employee is looking at [the] news and Slacking one of their friends to say, ‘do you think we’re going to update our policy?’” said Katie Burke, chief people officer at Cambridge-based marketing software firm HubSpot.

Burke sent a Slack message to HubSpot’s US employees earlier this week, including 1,800 based in Cambridge, to let them know the firm’s COVID-19 response team would meet to discuss potential policy changes. (Workers have been allowed in the Cambridge office on a voluntary basis since mid-June with no restrictions.)

HubSpot executives had already been thinking about reversing their decision not to mandate vaccines before employees returned in person. Burke said some, including those who are immunocompromised or have children too young for a vaccine, were “asking us to take a bit of a tougher stance.”

So on Thursday HubSpot told employees they would need to be vaccinated by September — those who opt out for medical or religious reasons would need to wear face coverings. HubSpot also hit the pause button on reopening certain office amenities, like the smoothie bar, until current concerns subside.

The communication was calm and measured, Burke said, and the company’s internal meetings were not filled with fear, anxiety, or tension.

“I don’t think anyone wants to take COVID guidance from someone who seems panicked,” she said. “We slept on it.”

HubSpot wasn’t the only big local employer to change course this week. Google, with nearly 2,000 employees in Massachusetts, said Wednesday that it would push its office reopening to mid-October from September, and it was one of the first big-name private companies to mandate vaccines for workers in the office. Facebook, which employs 500 people locally, said it would require vaccines, too.

Needham-based IDG, with 500 employees in Massachusetts, is still deciding what, if anything, needs to change in its reopening plan. The tech media company opened its headquarters at reduced capacity in June, but senior leaders met over Zoom on Tuesday to discuss how the resurgence of COVID might impact other offices that have not reopened. Just an hour later, the CDC issued its new mask guidance, so IDG’s COVID-19 task force is regrouping.

“What a difference a day makes, and what a difference a week makes,” said Laurie Butson, the company’s head of global talent engagement.

Many large employers in Massachusetts are still figuring out how to respond, or if they have they aren’t talking. Moderna and Biogen declined to share details about their return to office or vaccine protocols. DraftKings, State Street Corp., Wayfair, and Vertex Pharmaceuticals did not respond to requests for comment. (The Boston Globe told employees this week that its planned early September return to office will be pushed back to Columbus Day “at the earliest.” The New York Times said Friday it will delay indefinitely.)

Some are holding fast, for now.

Oct. 1 is the day cybersecurity firm Rapid7 plans to have 800 employees return to its Boston headquarters at least three times per week. As of Friday, those plans remained intact. But they will change if government officials and medical experts advise otherwise, said Jamie Kinch, Rapid7′s vice president of real estate and workplace experience.

“Every time we communicate a day it comes with 14 asterisks,” he said. “If the world changes, then we’ll adapt.”

And adapting has gotten easier. Last year, there was little information about the coronavirus and no vaccine. Today, many executives said they feel better equipped to make decisions.

“There’s less wide-eyed fear of the unknown,” said Tim Rowe, founder and chief executive of Cambridge Innovation Center. “We’re going to move into a living-with-the-pandemic normal: less of the emergency mentality and more of a practical, ‘OK how do we do this?’”

But this week, even “how do we do this,” has seemed to change by the day.

Pranshu Verma of the Globe staff contributed to this report.