Technically yes, there are viruses exist that target the Mac OS. Exactly ZERO of them can infect you unless you intentionally install them.
The newer Mac OS's require you to enter an admin's password when installing any software that can affect the system. In other words, the virus has to ASK to be installed and you have to say Yes by entering the password.
If you're dumb enough to do that, then you deserve any viruses and their consequences you get
