HPV prophylactic vaccination: The first years and what to expect from now

Abstract

New prophylactic HPV vaccines have the power to prevent many HPV infections, thus reducing the burden of HPV-associated diseases. Two vaccines composed of HPV L1 proteins self assembled into virus-like particles (VLPs) have been developed: one containing VLPS of HPV types 6, 11, 16 and 18, while the other vaccine is composed of HPV 16 and 18 VLPs. Large phase II and III clinical trials to assess prophylactic efficacy have been conducted in which both HPV infection endpoints and disease endpoints were evaluated, particularly high-grade cervical intraepithelial neoplasia--CIN2 or CIN3--as well as vulvar and vaginal intraepithelial neoplasias--VIN or VaIN--and genital warts for the quadrivalent vaccine. Very high efficacy rates were observed in different populations that included young women between 16 and 26 years of age, and older (up to 55). More recently, the quadrivalent vaccine has been shown to be efficacious in men to prevent genital and anal infection and disease caused by the types included in the vaccine. Based on demonstrated clinical efficacy and favorable safety profile, HPV prophylactic vaccine are being introduced worldwide aiming the reduction of the morbidity and mortality of tumors caused by HPV. From 2006 when first approved in the USA, hundreds of countries have licensed the HPV vaccines, a significant proportion of which are offering the vaccine to young women in national immunization programs supported by the government. The ultimate goal is to implement worldwide cervical cancer control programs to include HPV vaccination and screening with cytology and HPV DNA testing, particularly in less-developed countries where it is most needed.