Is it safer to run executable file (not safe, may contain virus) on VBox

I have a host system (Windows 10) with premium antivirus and running a Windows 7 in Virtualbox with no antivirus. I have installed sandboxie and try to run executable files that may contain virus. Is it safe to run those applications? and what will be the effect if the virus slips out. I know this is a dumb question even after knowing about sanboxie. But I would like to know the consequences that occur.

Also, I would like to know how it affects the host machine if I run that exe file without sandboxie on Virtualbox.

Since there are many viruses and trojans that silently triggers even without running the exe file. Just want to learn the consequences that virus can damage. (P.S that I still having the antivirus on on the host machine).