Human papillomavirus 68 (HPV68) is a mucosotropic member of the Alphapapillomavirus genus. It has a circular double-stranded DNA genome and is considered a high-risk or probable high-risk type because persistent infection can lead to neoplastic changes.
Virology & Oncogenic Mechanisms
HPV68 belongs to the alpha 7 species group of papillomaviruses and includes two sublineages (68a and 68b). Its genome encodes early regulatory proteins (E1–E7) and late structural proteins (L1–L2). The E6 and E7 oncoproteins of HPV68 interact with p53 and retinoblastoma proteins, promoting cell cycle progression and impairing apoptosis, although their transforming activity is less efficient than that of HPV16 and HPV18. The virus infects basal keratinocytes through microabrasions, establishes its genome as an episome and replicates as cells differentiate. Integration of viral DNA into the host genome with persistent E6/E7 expression can contribute to oncogenesis. While HPV16 and HPV18 are responsible for most HPV related cancers, other types including 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59 are recognised as high risk; HPV68 is classified as probable high risk and shares similar biological features.
Clinical Impact and Prevention
HPV68 infection is uncommon but has been detected in cervical intraepithelial neoplasia and a small number of invasive cervical cancers. It may also occur in anal and oropharyngeal lesions, though associations are less clear. Most infections are transient and cleared by host immunity; persistence is more likely in individuals with compromised immune systems. HPV68 is not included in current prophylactic vaccines, so prevention depends on reducing transmission and early detection. High‑risk HPV DNA tests often detect HPV68 as part of “other high‑risk” types, and Pap cytology remains important for screening. Barrier methods, vaccination against covered types to reduce co‑infection and smoking cessation help lower the risk of persistent infection. HPV68 is a probable high‑risk papillomavirus whose persistent infection may contribute to cervical and other anogenital cancers, albeit infrequently. Continued surveillance and preventive measures are essential given its exclusion from current vaccines. Related Terms: HPV66, HPV45, Probable high‑risk HPV, Alpha 7 species, Viral oncogene