School Advice

So with the delta variant on the rise and cases spiking in our state I’m honestly debating not having my almost 5 year old start kindergarten. It’s not mandatory in our state and he will be five one Monday. I’m wondering if he can just do kindergarten at 6 or just start 1 grade next year instead. But with vaccinated people even getting it, how are any of us safe from it?! I have a one year old to also worry about. I just don’t want my 5 year old to bring anything home or get sick. Am I being overly dramatic? Help! Please no negative rude comments.