Autorun.inf in USB flash drive has long been used in such a way to infect computers, yet there are still many antivirus programs that ignore its existence. Your installed antivirus will likely to block the attack executed from autorun.inf, but the autorun.inf in the USB pen drive will most likely be untouched. It means the source of the attack will stay alive and will attack again when the USB flash drive is re-connected. Thus, to prevent infection from autorun.inf, you should remove autorun using a tool like Autorun Eater.
Autorun Eater monitors your system in real time and, depending on your preference, it will automatically remove autorun.inf or ask you what it should do when an autorun.inf is detected. Instead of removing the detected autorun.inf permanently, the program will move the file to a safe backup in case of a false positive. All in all, this is a good alternative if you want to have an easy-to-use autorun remover. However, you can consider about using USB Anti Autorun if you prefer to disable USB autorun.