Here are some excellent explainers:
BrainPOP - A surprisingly entertaining, at times humorous, basic explanation of COVID-19 and needed precautions for elementary age children and young teens.
Little Puddins - The Autism Educator - Little Puddins Blog has a nice "Coronavirus Social Story."
NPR's Goats & Soda - Basic information for youth in a graphic format that can be read in the Blog or downloaded and folded into a zine.
We're Going to Be OK - Staying safe, healthy, and optimistic during the COVID-19 pandemic. eBook written by Dr. Ebony Jade Hilton and Dr. Leigh-Ann Webb; Illustrated by Ashleigh Corrin Webb