Airborne viruses are droplets in the immediate environment, much like catching the common cold or flu. This allows the virus to spread quickly from person to person, but it doesn’t mean every person who comes into contact with it, will immediately be affected.
This comes down to certain factors, including the strength of the individuals immune system.
It’s also possible for some to resist viruses, provided their immune is up to the challenge.
This is similar to those who manages not to get sick, when everyone else in the household …