SEATTLE (AP) — Amazon has pushed back its return-to-office date for tech and corporate workers until January as COVID-19 cases surge nationally due to the more contagious delta variant.

Unlike its Seattle-area rival Microsoft and other tech giants, Amazon will not mandate employees receive the COVID-19 vaccine before they return to the office. Instead, the company said Thursday that unvaccinated employees will be required to wear masks in the office.

The surge of the delta variant of the coronavirus has upended many companies' plans to bring office workers back this fall, a drive already complicated by efforts to accommodate widespread employee preference for flexible remote work policies, and debates over how to handle vaccine and masking policies.

Other companies that have postponed reopening plans include Microsoft, Google, Twitter and Lyft.

Amazon, which had previously set a Sept. 7 return date, said employees will now be expected to report to it U.S. offices on Jan. 3, according to plans previously reported by The Seattle Times. Amazon is also implementing a hybrid work plan that will allow many corporate employees to continue working from home at least two days a week.

The delay affects the roughly 60,000 people working in Amazon's offices in Seattle and Bellevue, Washington, as well as tens of thousands more corporate Amazon employees worldwide. Amazon is Washington state's largest private employer, and the delay in the return to office work will be a blow to the many downtown Seattle businesses that rely on the trade of tech workers.

The vast majority of Amazon's 1.2 million-person global workforce is still expected to show up on-site to pack boxes, sort merchandise and load and unload trucks at Amazon warehouses.