How does it spread from humans to deer? Do you have to sneeze at the deer, or be in the same room? And how can it transmit back? I thought it was an airborne virus...
My impression was that being outside virtually eliminated transmission; I can’t imagine people bring deer indoor — are people nuzzling their faces into deer???
Probably from breath. It jumped from humans to deer in the first place, meaning that such encounters do occur. And since COVID is hardly recognizable from normal flu without a test, even one such encounter is enough to restart the pandemic.