Nothing could go wrong if you spread an illness to dozens of kids who then interact with hundreds of kids who then interact with thousands of family members at home. Go to work and touch all the same surfaces as the other drivers before driving your very heavy bus.
Wouldn't an insurance company love to see this.
So you want your drivers to be infectious, half alert, with a multi ton large vehicle with lots of kids lives in the balance in often adverse weather?
Also hey parents to save costs we're allowing zombies to drive your kids now.