ClamAV is an OK antivirus, if you use it to scan annex files on a mail server or cloud storage.
Is now suitable for real time scan.

Virus detection is very poor, it let pass many virus
https://www.splunk.com/en_us/blog/security/how-good-is-clamav-at-detecting-commodity-malware.html

Keep in mind that ClamAV does not disinfect files. It only removes them from the system or moves them to a specified location. It also doesn't watch for infections. It scans when you ask and otherwise remains dormant.

https://www.networkworld.com/article/3652690/using-clamav-to-detect-and-remove-viruses-on-linux.html