Can I (a vaccinated parent) transmit the virus to my (unvaccinated) kids?
Yes. During pre-Delta, vaccines reduced transmission by a lot (85-90%), but they’re not perfect (100%). So, yes you can give the virus to your kids, although it’s much less probable than an unvaccinated person. We do not know how Delta changes the game. Delta is stickier with a higher viral load, so Delta has the potential to transmit from vaccinated to unvaccinated higher than before. But we just don’t know yet.
An epidemiologist looks at the Delta variant's impact on kids who can't get vaccinated yet.