The New Normal: Should everyone, including vaccinated people, be putting their masks back on?

News 12's Danielle Campbell was joined this morning by Dr. David Battinelli, the chief medical officer at Northwell Health, to discuss the delta variant and masks.
The White House is reportedly in talks with the Centers for Disease Control and Prevention on whether to push for updated mask guidance amid a surge in delta variant infections across the country.
Do you see another public mask mandate coming soon? Does this include those who are vaccinated? Do you recommend mask wearing in large gatherings and public places despite what the CDC decides?
What do we know now about the delta variant? How quickly does it spread, and does it cause severe sickness, like the earlier versions of the coronavirus?
Health officials have warned that the country is now facing a "pandemic of the unvaccinated," as areas with relatively low vaccination rates are now experiencing surges in coronavirus infections and hospitalizations. For those who are unvaccinated, how serious is the Delta variant for them?
What about those so-called "breakthrough" cases? What about boosters?
During a CNN town hall President Joe Biden said the CDC would likely be issuing guidance encouraging children who have not been vaccinated to wear masks when they return to schools in the fall. Is this a good idea?