endIndex: (CNN) — The US Centers for Disease Control and Prevention has changed its guidance to once again recommend that even vaccinated people start masking indoors in areas of the country with high and substantial coronavirus spread. Key to their decision was a study that shows that fully vaccinated people can still transmit the Delta variant. At the same time, Disney, Netflix, Google, Walmart and the federal government announced plans to implement some type of vaccine requirement for employees returning to in-person work. Is it safe for vaccinated people to return to work if vaccine mandates are in place? What if they are not -- is masking enough, and what if others around you are unvaccinated and not wearing masks? What about workers who have children too young to be vaccinated?