The game is more realistic to real virus spread because not all neighbors can be infected immediately--more like super simple Go, some pockets escape.

edit: Woo hoo! Here's the math for the real life situation which the game mimics: https://wattsupwiththat.com/2020/05/11/why-herd-immunity-to-covid-19-is-reached-much-earlier-than-thought/ mentioned in a post by u/nufosmatic

The game is more realistic to real virus spread because not all neighbors can be infected immediately--more like super simple Go, some pockets escape.