(AP) — Google is once again postponing a return to the office for most workers until mid-January. The internet search giant is also to requiring all employees to be vaccinated once its sprawling campuses are fully reopened.

The highly contagious delta variant of the coronavirus is driving a dramatic spike in COVID-19 cases and hospitalizations. That is leading companies to delay or scrap return-to-office plans after nearly two years of people working from home.

CEO Sundar Pichai said in a blog post Tuesday that Google is delaying its return to offices until Jan. 10.