Human papillomavirus types 6, 11, 16, 18, 31, 33, 45, 52, and 58 L1 capsid protein (HPV 6/11/16/18/31/33/45/52/58 L1)

Human papillomavirus (HPV) types 6, 11, 16, 18, 31, 33, 45, 52, and 58 are double-stranded DNA viruses that infect cutaneous and mucosal epithelial tissues (CDC, 2021). The L1 protein is the major capsid protein of these viruses and serves as the primary target for neutralizing antibodies induced by vaccination (Schiller & Lowy, 2018). These specific types are categorized into low-risk types (6 and 11), which cause approximately 90% of genital warts, and high-risk types (16, 18, 31, 33, 45, 52, and 58), which are responsible for the majority of HPV-related cancers, including cervical, anal, and oropharyngeal malignancies (FDA, 2020). The 9-valent HPV vaccine utilizes recombinant L1 proteins assembled into non-infectious virus-like particles (VLPs) to elicit a robust humoral immune response (Merck & Co., 2023). Upon exposure to the wild-type virus, these vaccine-induced antibodies bind to the L1 protein on the virion surface, sterically hindering viral attachment to the basement membrane and preventing entry into basal keratinocytes (Buck et al., 2013). This neutralization effectively prevents persistent infection and the subsequent progression to pre-cancerous lesions and invasive carcinoma.

Other names

9-valent HPV vaccine targetNonavalent HPV vaccine targetHPV L1 virus-like particles (VLPs)HPV 6/11/16/18/31/33/45/52/58 virionsHuman papillomavirus major capsid protein L1

Vaccine-induced IgG antibodies bind to conformational epitopes on the L1 capsid protein of the HPV virions, neutralizing the virus by preventing its attachment to the host cell surface and subsequent internalization (Schiller & Lowy, 2018; FDA, 2020).