Major US companies are having to reassess their return-to-office plans and getting tough on vaccine or mask requirements as the Omicron Covid variant looks set to extend pandemic-induced work-from-home culture. A resumption of pre-virus workplace norms was only partially moving forward in the United States when the fast-spreading new variant arrived and provoked fresh concern.

Legal challenges have made the future of President Joe Biden’s vaccine mandate for companies with over 100 workers uncertain, and firms have been pursuing their own requirements. Tech giant Google has been notably uncompromising in warning employees of lost pay or even dismissal if they do not report their vaccination status by a particular deadline, according to an internal document viewed by CNBC.

“We firmly believe that our vaccination requirements are one of the most important ways we can keep our workforce safe and keep our services running,” Google told AFP. The search engine giant has also postponed indefinitely the return to the office of its engineers and developers, originally scheduled for January.