Publicis Groupe is pushing off its return to the office in the U.S. as the Delta variant sweeps across the country. 

The holding company officially reopened its U.S. offices on a voluntary basis in July, but staffers were not required to go in. 

Initially, Publicis planned to have staffers return to the office in a hybrid capacity after Labor Day. But on Wednesday, Publicis’ HR team sent a note to staff, obtained by Campaign US, that updates the policy to say that the group will delay any decisions regarding a mandatory return to the office until Q4. 

“Coming to the office at this time remains optional,” the note says. 

All decisions in regard to office reopenings will continue to be made at the local market level, according to the note. Voluntary office goers must complete a safety training on Marcel, the group’s digital connectivity and talent platform, as well as a daily health questionnaire before entering a Publicis office building.

Publicis will not require staff to be vaccinated to return to its offices voluntarily, but unvaccinated people will be required to wear masks at all times, the note says. The company also “strongly recommends masking for all employees in all of our offices, regardless of vaccination status,” unless working in an enclosed space. 

Publicis also promised that regardless of when employees come back to the office, “flexibility will continue to be key in our future plans.”

The note urges employees to treat each other with empathy and remain flexible as the situation evolves. 

Other major holding companies, also eyeing a fall return, have not yet made statements about pushing back their office reopenings. However, according to a source, Omnicom, which requires employees to be vaccinated to work from its offices, canceled an in-person town hall meeting for one of its agencies in September and switched it to a virtual event.

Both Omnicom and IPG indicated that a return to the office was coming on their Q2 earnings calls in July, warning investors that costs would start to rise for real estate and travel starting in Q4. 

Campaign US contacted WPP, Omnicom, IPG, Havas and Dentsu to comment for this story and has not heard back.

COVID-19 cases in the U.S. have spiked in recent weeks as a result of the Delta variant, which is more contagious than other strains of the virus and can be spread by vaccinated individuals. According to the CDC, as of Saturday, there were roughly 72,000 cases per day in the U.S., a 44% increase over the prior week. 

After an optimistic summer in which agencies and marketers were getting back out into the market and office reopenings seemed like a sure thing, many have already started slowing down business travel and rethinking their plans for the rest of the year.