What is the best way to protect from polymorphic viruses?

What is the best way to protect from polymorphic viruses?

Due to malware infections becoming more and more common, antivirus are a growing industry.

But it is common knowledge that polymorphic viruses (that rewrite their own code) are much harder to detect and remove with AVs.

This source, as well as numerous other ones, explains that:

A polymorphic Virus can continue to alter the signature and attack undetected even after a fresh signature is found and added to the antivirus solution's signature database.

So what is the best way to protect against polymorphic virus infections, in general?

Are there specific protocols/ methodsor is it just the same as other viruses?