There aren't really any virus' that affect AIX - make sure that you're up to date with your security patching to eliminate any vulnerabilities that could be used to gain access or elevate privileges.
AIX can be a conduit for virus' that affect other platforms though. If you're using AIX as a file & print server (samba) then scanning the hosted files for virus' is a VERY good idea.
Trend Micro Deep security has an AIX agent that performs virus scanning on AIX. If your organisation is already using Trend for other platforms, then it could be a good option:
https://help.deepsecurity.trendmicro.com/20_0/on-premise/agent-compatibility.html#:~:text=Trend%20Micro%20releases%20agents%20for%20major%20Linux%20versions%2C,they%20use%20a%20kernel%20supported%20by%20the%20agent.
https://help.deepsecurity.trendmicro.com/20_0/on-premise/supported-features-by-platform.html#AIX