With coronavirus infections on the rise, the highly contagious Delta variant is throwing a wrench into the country's re-opening plans and general hot vax summer vibes. That's causing government agencies and employers to modify — and sometimes take a harder line on — vaccination requirements as workers return to offices.

Until recently, Twitter was the only big tech company requiring employees who wanted to work from company offices to be vaccinated.

That changed triple-fold Wednesday. Google CEO Sundar Pichai announced in an email to employees, and in a public-facing blog, that Googlers would need to have their COVID-19 vaccines in order to work from Google offices. Facebook made the same announcement a few hours later. And shortly after that, Twitter went even further and re-closed its offices, citing the Delta variant and risk of infection as the cause.

"After careful consideration of the CDC's updated guidelines, and in light of current conditions, Twitter has made the decision to close our opened offices in New York and San Francisco as well as pause future office reopenings, effective immediately," a Twitter spokesperson said via email. "We’re continuing to closely monitor local conditions and make necessary changes that prioritize the health and safety of our Tweeps."

Google already has some of its offices open for employees who individually want to go in to work. In the same message, Pichai said the company is extending its "voluntary work-from-home policy" through October 18. Meaning, by October 18, Google employees will be headed back to work — vaccinated, if they want to get through the doors.

The last 15 months of the pandemic have been a rollercoaster of closures, openings, closings again. Of vaccine drives, vaccine hesitancy, receding viruses and spikes that come roaring back. Big tech organizations have made policies based on the current moment, and have had to reassess, just like the rest of us.

Unfortunately, the best available public health information has not seemed to be the only factor at play in these decisions. Getting vaccinated became a politicized issue along party lines as some conservatives conflated the public health move with an issue of personal freedom. At the same time, tech companies accused of (unproven) anti-conservative bias are trying not to piss off Republican users and lawmakers, all while antitrust legislation hangs over their heads.

The companies say their employee vaccination policies are based on health and science. But when it comes to public perception of Big Tech, there's always more at play. That's why Google and Facebook instating their employee vaccination policies is a bigger deal than it should be: It's staking the companies' flags on the side of public health, despite potential political backlash.

As the virus, health guidance, and public opinion mutates, so too are tech company policies. Here's where big tech companies stand on employees returning to work and whether they need to be vaccinated or not.

Google

The company reversed a previous policy of encouraging but not requiring vaccinations on July 28. A Google blog post announced "anyone coming to work on our campuses will need to be vaccinated." The policy will begin in the U.S., and will eventually expand to other regions as vaccines become more widely available. Some employees can receive exemptions for health and "other protected reasons" (Google declined to expand on what those reasons are).

Facebook

The social media giant issued a statement to the media Wednesday announcing new vaccination requirements for U.S. employees.

"As our offices reopen, we will be requiring anyone coming to work at any of our US campuses to be vaccinated," Lori Goler, Facebook's vice president of people, said in an emailed statement sent to Mashable. "How we implement this policy will depend on local conditions and regulations. We will have a process for those who cannot be vaccinated for medical or other reasons and will be evaluating our approach in other regions as the situation evolves. We continue to work with experts to ensure our return to office plans prioritize everyone's health and safety."

Meanwhile, Facebook is one of the most influential sources of anti-vaccine misinformation.

Amazon

Amazon is not requiring employees to be vaccinated, the company said via email. Vaccinated employees do not have to wear masks (though they can if they want to), while the company requires unvaccinated employees to don the face coverings.

However, the policy is not entirely consistent across all Bezos-owned companies. Since 2013, Jeff Bezos' holding company Nash Holdings has owned the Washington Post.The Post'spublisher informed employees on Tuesday that anyone returning to the office in September would need to show proof of vaccination.

Tweet may have been deleted

Twitter

Twitter has instated a permanent voluntary work from home policy. For those wishing to come back to the office, Twitter re-opened some of its offices in May, and required employees coming to work to be vaccinated.

But on Wednesday, Twitter re-closed its offices. So the issue and vaccine policy is moot for now.

Apple

Apple CEO Tim Cook reportedly told CNBC Tuesday that the company has yet to decide on its employee vaccine policy. That's because offices for corporate employees aren't even open yet, and it just recently pushed back re-opening until at least October.

Tweet may have been deleted

Netflix

The streaming behemoth joined in on the vaccine announcements fun on Wednesday, too. Sort of. According to Deadline, Netflix will require vaccinations for "zone A personnel" on film and TV sets. That includes actors and the on-set crew that work directly with actors. There's no word yet on whether the policy will extend to Netflix's corporate offices.

Uber and Lyft

Both Uber and Lyft updated their policies this week, requiring corporate employees who return to each company's respective offices to be vaccinated. Uber's offices will re-open in October, while Lyft's won't be opening back up until February 2022. Neither company is requiring vaccinations for drivers at this time.

Microsoft

The Washington-based company confirmed a new mandatory U.S. vaccine policy to CNN on August 3. When its offices reopen in October, all "employees, vendors, and guests" will have to show proof of their vaccination status.