HPV prophylactic vaccines: Second-generation or first-generation vaccines

Abstract

High-risk genotypes of human papillomavirus (HPV) are associated with genital cancers especially cervical cancer. United State Food and Drug Administration (USFDA) has recently licensed two first-generation prophylactic vaccines ( i.e. , Gardasil and Cervarix), for control of HPV 16 and 18 infections. Both vaccines are able to generate neutralizing antibodies against major capsid protein L1 assembled as virus-like particles (VLPs). To enhance protection against other HPV genotypes, second-generation vaccines are underway. A HPV L1-based nonavalent vaccine showed is potent and safe in prevention of precancerous lesions associated with HPV types 16/18/31/33/45/52/58, as well as anogenital warts associated with HPV types 6/11. This vaccine is in the advanced stage of phase III clinical trials. Other second-generation vaccines were based on L1-pentameric subunits and also the minor capsid protein L2 that have shown to be effective in preclinical studies. The L2 protein co-assembles with the L1 protein for VLP formation increasing virion aggregation. This mini-review describes two vaccination strategies including first-generation and second-generation vaccines against HPV infections.