Pfizer Inc.’s US employees will be required to return to their workplaces two to three days a week starting in January, Chief Executive Officer Albert Bourla said.

Almost three years after the pandemic began, about a third of Pfizer employees still have not been back to the office, Bourla said November 8 in a panel discussion at the Paley International Council Summit in New York.

Pfizer teamed with BioNTech SE to develop highly effective COVID-19 vaccines at top speed during the pandemic, when many employees were working from home, and then generated the Paxlovid pill for treating people at high risk of severe disease. Both products have been highly successful for the company.

Some of Wall Street’s biggest companies, including Goldman Sachs Group Inc., have been in the vanguard of those pulling employees back into the office as concerns about the pandemic have begun fading. Tesla Inc. CEO Elon Musk has also worked to get employees quickly back into traditional workspaces.

“I started to worry we were going to lose the DNA of our company, the feeling of family,” Bourla said in the discussion. “For our workforce, people with office-type jobs, we are asking them, and will start enforcing a two to three days” of weekly attendance, he said.

Going back to full attendance isn’t possible, he said, and workplace flexibility has helped with productivity levels and quality of life.

“We’re trying to see how we can play our cards so that we can save the world once again,” Bourla said.