Human papilloma virus vaccines: Current scenario

Abstract

Genital human papillomavirus (HPV) infection is the most common sexually transmitted infection with an estimated worldwide prevalence of 9-13% and approximately 6 million people being infected each year. Mostly acquired during adolescence or young adulthood, HPV presents clinically as anogenital warts and may progress to precancerous lesions and cancers of the cervix, vagina, vulva, penis and anus, and oropharynx. HPV infection is considered to contribute to almost 100% cervical cancers and at least 80% of anal and 40-60% of vulvar, vaginal, and penile cancers. At present, two prophylactic HPV vaccines are commercially available and both are prepared from purified L1 structural proteins. These proteins self-assemble to form virus-like particles that induce a protective immunity. Gardasil(®) is a quadrivalent vaccine against HPV types 6, 11, 16, and 18 and is recommended for use in females 9-26 years of age, for the prevention of cervical, vulvar, and vaginal cancers and intraepithelial neoplasia and condyloma acuminata and recently for vaccination in boys and men 9-26 years of age for the prevention of genital warts. Cervarix™ is a bivalent vaccine approved for the prevention of cervical cancer and precancerous lesions caused by HPV 16 and 18, in females 10-25 years. HPV vaccines are safe and efficacious against type-specific HPV-induced anogenital warts, precancerous lesions, and cervical cancer. The vaccines are most effective when given before the onset of sexual activity and provide long-term protection. Effective vaccination coverage in young adolescent females will substantially reduce the incidence of these anogenital malignancy-related morbidity and mortality. There is need to generate India-specific data on HPV epidemiology and HPV vaccination efficacy as well as continue worldwide surveillance and development of newer vaccines.