First question, depends on the virus.
Some viruses are pretty fragile while others are quite hardy.
I don't know what would happen to the effectiveness of your tobacco emulsion as a pesticide after boiling. The answer is antibiotics are completely ineffective against virus. The are toxic to various bacteria, not viruses. Requires expert analysis. You could take guesses as to what virus it might be, and check to see if you were correct using some sort of specific test, usually based on an antibody specific to that type of virus.