Google is once again postponing a return to the office for most workers until early 2022, in addition 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 coronavirus cases and hospitalizations, leading companies to delay or scrap return-to-office plans after about one-and-a-half years (and counting) of white-collar staff working from home due to the coronavirus pandemic.

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Sundar Pichai, Google’s chief executive officer, said in a blog post that the company is delaying its global return to offices until Jan. 10, 2022. After that, he said the company will let countries and locations determine when to end voluntary work-from-home policies “based on local conditions, which vary greatly across our offices.”

He also promised a 30-day heads up before workers are expected back in the office. This is the second time in a little over a month that Google has delayed return plans — the last time was in late July, when it also announced its vaccine mandate. Google, which is headquartered in Mountain View, Calif., has more than 130,000 employees worldwide.

Several other U.S.-headquartered employers, including Inc., Apple Inc., Starbucks Corp. and Uber Technologies Inc., have also reportedly moved back return-to-office dates until 2022.

Read: Twitter among growing list of Canadian employers, governments enacting vaccination policies