Homeless people would drop like flies if they didn't have fairly good immune systems from being outside a lot and from being exposed to germs and viruses due to their surroundings.

EDIT - how is this incorrect? Looking at some of their surroundings, homeless people must have fairly good immune systems as a group. It's because they are outside (Vitamin D and C) and are active. Most aren't obese. Most aren't older than 60s. Guess that bot got me...

Homeless people would drop like flies if they didn't have fairly good immune systems from being outside a lot and from being exposed to germs and viruses due to their surroundings.