If you interact with other people, you can’t will yourself out of exchanging some bacteria and viruses with them. The only way to kind of avoid it is to totally isolate yourself from any contact, total 2 meters away from everyone forever, which a person working at an airport physically can’t do
People who live with people with compromised immune systems and take great care not to spread germs can absolutely avoid catching colds for decades.
If you interact with other people, you can’t will yourself out of exchanging some bacteria and viruses with them. The only way to kind of avoid it is to totally isolate yourself from any contact, total 2 meters away from everyone forever, which a person working at an airport physically can’t do