HCQ together with zinc acts as a general anti-viral.

HCQ works by changing the PH of the virus capsid (body) and allows zinc ion to penetrate into the virus thereby halting the virus's ability to reproduce.

It's not "binder dependant" which means it doesn't work to keep the specific viruses from attaching to specific cells in the body. It works against most, if not all, viruses by simply shutting them down and not letting them replicate.

This has been known for a long time.