By any chance have you once been down with acute rhinitis? By any chance did you do away with the infection? Of course you recovered! You can't heal a runny nose itself, yet your system normally develops resistance to any cold virus within a few days. That is called cured by your very own immune response! Human papilloma virus is comparable in that HPV virus is simply another virus. Therefore you can quite simply develop immunity to HPV virus. Nonetheless, HPV is much better at hiding from your