Efficacy and safety of human papillomavirus vaccine for primary prevention of cervical cancer: A review of evidence from phase III trials and national programs

The Human Papillomavirus (HPV) vaccines have been widely introduced in the national immunization programs in most of the medium and high income countries following endorsement from national and international advisory bodies. HPV vaccine is unique and its introduction is challenging in many ways – it is the first vaccine developed to prevent any cancer, the vaccine is gender specific, it targets adolescent females who are difficult to reach by any health intervention programs. It is not unusual for such a vaccine to face scepticism and reservations not only from lay public but also from professionals in spite of the clinical trial results convincingly and consistently proving their efficacy and safety. Over the last few years millions of doses of the HPV vaccine have been administered round the world and the efficacy and safety data have started coming from the real life programs. A comprehensive cervical cancer control program involving HPV vaccination of the adolescent girls and screening of the adult women has been proved to be the most cost-effective approach to reduce the burden of cervical cancer. The present article discusses the justification of HPV vaccination in the backdrop of natural history of cervical cancer, the mechanism of action of the vaccines, efficacy and safety data from phase III randomized controlled trials as well as from the national immunization programs of various countries.