Prevention of cancer by prophylactic human papillomavirus vaccines.

Oncogenic human papillomaviruses (HPVs) are exclusively mucosal pathogens that are noncytopathic and the basal epithelial cells harboring and maintaining an infection do not produce either capsid antigen or virus. The efficacy of the licensed L1 virus-like particle (VLP) vaccines has encouraged development of several second generation vaccines aimed at expanding the coverage to all oncogenic HPV types and reducing barriers to global implementation. Currently there is no defined immune correlate of protection that can be used to determine if an individual patient is protected and for the evaluation of these second generation vaccines. Surprisingly, passive transfer of neutralizing serum antibody is protective in animal models. Recent studies suggest how neutralizing antibody mediates immunity against mucosal HPV and the possible impact of memory B cells.