" In other words, I would say: "I need to get rid of that tick which is been biting me all day long." I would not say: "I must be free from that tick." And that's why I would use "rid of" with a cold, as an alternative to "free" https://share.evernote.com/note/c797b48b-9e6d-224c-1b35-99cb7e6200bb