“In fact, rabies is extremely rare in opossums, perhaps because they have a much lower body temperature compared to other warm-blooded animals.”
They do have a natural immunity to rabies thanks to their body, but immunity does not always mean 100%. They have a lot lower risk of it, which means they are more immune than other animals.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5120391/
“In fact, rabies is extremely rare in opossums, perhaps because they have a much lower body temperature compared to other warm-blooded animals.”
They do have a natural immunity to rabies thanks to their body, but immunity does not always mean 100%. They have a lot lower risk of it, which means they are more immune than other animals.