Google CEO Sundar Pichai on Wednesday told employees the company will require vaccinations for employees working on the company’s campuses, a move that comes as the highly contagious delta variant of the COVID-19 virus spreads across the world. The policy will begin in the US and expand to other regions over the next few months.

Pichai also delayed the company’s mandatory return to office to Oct. 18, pushing back the date from an earlier goal of September.

«Getting vaccinated is one of the most important ways to keep ourselves and our communities healthy in the months ahead,» Pichai wrote in an email to employees. «I know that many of you continue to deal with very challenging circumstances related to the pandemic.»

Pichai said the policy will be implemented according to local conditions, and he would share guidance and exceptions for people who can’t get vaccinated due to medical or other protected reasons.

The announcement comes as regions around the world have seen coronavirus cases surge due to the delta variant. In California, Google’s home state, some counties have mandated masks again for people gathering indoors.

Google isn’t alone in re-evaluating its return-to-work protocols because of the latest wave of the pandemic. Apple said last week that it would also postpone its date for returning to the office by a month. More than half of Apple’s stores will require customers and employees to wear masks, regardless of vaccination status, starting on Wednesday, according to Bloomberg.

Facebook also said on Wednesday that it would require workers on its US campuses be vaccinated. Netflix will require vaccinations for casts of its US productions, Deadline reported. Twitter said it’s closing the company’s opened offices in New York and San Francisco and pausing future office re-openings. The company said that the office closures are temporary but they don’t have a new timeline for reopening. «We’re continuing to closely monitor local conditions and make necessary changes that prioritize the health and safety of our Tweeps,» a Twitter spokesperson said in a statement.

Uber on Thursday also pushed its global return to office date back to Oct. 25, a delay from its original goal of September. In an internal note to employees, which an Uber representative shared with CNET, CEO Dara Khosrowshahi added that «local circumstances will continue to dictate when it makes sense to bring employees back in a given city,» and that some offices will remain open for employees to come into voluntarily, if local health guidelines allow. Uber will also require employees be fully vaccinated to come into the office, beginning in the US before expanding to other countries. In addition, all Uber employees around the world must now wear masks if they’re in the office.

Google’s return-to-office policies have caused major tension among the tech giant’s employees, who have complained the rules are applied unevenly. Earlier this month, CNET reported that Urs Hölzle, one of Google’s most senior and longest tenured executives, told employees he’d be working remotely from New Zealand. The announcement rankled lower-level workers who called the relocation «hypocritical» because they said he had in the past been unsupportive or remote work.

CNET’s Queenie Wong and Abrar Al-Heeti contributed to this report.