The highly contagious Delta virus is causing problems for the country's plans to reopen and its hot vax summer vibes. This is causing employers and government agencies to adjust and sometimes take a more strict line on vaccine requirements for workers returning to work.Twitter was the only tech company that required employees to have vaccinated if they wanted to work in company offices.This was changed three-fold on Wednesday. Sundar Pichai, Google's CEO, announced via email to employees and on a blog that all Googlers must have their COVID-19 vaccinations to work in Google offices. A few hours later, Facebook made the same announcement. Twitter followed suit and closed its offices again, citing the risk of infection and the Delta variant.Twitter spokesperson, via email, stated that Twitter had made the decision to close its offices in New York City and San Francisco, as well as to halt future office reopenings. This was after careful consideration of the CDC's updated guidelines. "We are continuing to monitor local conditions and make changes that prioritize safety and health for our Tweeps."Google has already opened some of its offices for employees who wish to work. Pichai also stated that the company will continue its voluntary work-from-home policy until October 18. Google employees will need to be vaccinated before they can return to work on October 18.The last 15 months have seen a rollercoaster ride of closings, openings and closings. There were vaccine drives, vaccine hesitancy and receding virus, as well as spikes that came roaring back. Big tech companies have made policies that are based on the moment and have had to revise, just as the rest of us.These decisions are not made solely on the basis of the best public health information available. Because some conservatives confused the issue of vaccination with a matter of personal liberty, getting vaccinated became a partisan issue. While antitrust legislation hovers above their heads, tech companies are being accused of an (unproven), anti-conservative bias.According to the companies, their employee vaccination policies are based upon science and health. There's always more to Big Tech when it comes down to public perception. Google and Facebook's announcement of their employee vaccination policies is an important deal. It's taking the companies' flags to the side for public health, despite possible political backlash.Tech company policies change as the virus, public opinion, and health guidance evolve. Here are the positions of major tech companies regarding employees returning to work, and whether or not they should be vaccinated.GoogleOn July 28, the company changed its previous policy that encouraged but did not require vaccinations. In a Google blog post, it was stated that "anyone who works on our campuses must be vaccinated." The policy will be implemented in the U.S. and will expand to other countries as more vaccines become available. Employees can be granted exemptions for "other protected reasons" and health (Google has declined to elaborate on these reasons).FacebookSocial media giant, Twitter, issued Wednesday's statement to media announcing that new vaccination requirements were in place for U.S. workers."As our offices reopen we will require anyone coming to work on any of our US campuses be vaccinated," Lori Goler (Facebook's vice president for people) said in an email statement to Mashable. "The local regulations and conditions will determine how we implement this policy. We will provide a procedure for people who are unable to be vaccinated due to medical reasons or any other reason. As the situation changes, we will also evaluate our approach in other areas. We are continuing to work with experts in order to ensure that our return to office plans prioritise everyone's safety and health.Facebook, however, is one of the most powerful sources of anti-vaccine misinformation.AmazonAmazon does not require employees to have their vaccines, according to the company via email. The company does not require employees who have been vaccinated to wear masks, but they are allowed to do so if they wish. However, it requires employees who aren't vaccinated to use them to cover their faces.TwitterTwitter has established a permanent voluntary home-work policy. Twitter has reopened its offices to employees who wish to return to the office. In May, it required that all employees be vaccinated before they could return to work.Twitter closed its offices on Wednesday. The issue of vaccine policy and its implications are now moot.AppleCNBC reported Tuesday that Apple CEO Tim Cook said to CNBC that they have yet to decide on their employee vaccination policy. This is because the offices for corporate employees have not yet opened and was delayed until October.NetflixThe streaming giant joined the fun of Wednesday's vaccine announcements. It's sort of. Deadline reports that Netflix will require vaccinations for all "zone A personnel" working on TV and film sets. This includes actors as well as the crew on set who work directly with them. Netflix's corporate offices are not yet covered by the policy.This is a developing story. We will keep updating this list as Big Tech (and everyone else) continue to weather the pandemic.