Vaccination against HPV virus
The HPV vaccines target the HPV types that most commonly cause cervical cancer and can cause some cancers of the vulva, vagina, anus, and oropharynx. It also protects against the HPV types that cause most genital warts. FDA has approved three vaccines for prevention of HPV infection: the bivalent (Cervarix), the quadrivalent (Gardasil) and the new 9-valent (Gardasil 9).
These vaccines prevent infections with two, four and nine types of the human papillomavirus. All of them prevent infections with HPV types 16 and 18 which cause pre-malignant dysplasia. Furthermore, the quadrivalent vaccine prevents infections with 6 and 11 types which are responsible for causing 90% of genital warts. Gardasil 9 prevents infection with the same four HPV types plus five additional high-risk HPV types (31, 33, 45, 52, and 58). The 9-valent vaccine increases the protection against HPV by preventing most cervical cancers and reducing the incidences of other HPV-associated cancers.
None of the above vaccines contain the virus itself or any of its parts. Essentially, it contains recombined artificial proteins which are non-infectious, because they lack the DNA virus . These proteins mimic the natural infection and stimulate the immune system to develop adaptive immunity to the pathogen. The current HPV vaccines are based on virus-like particles (VLPs) that are formed by HPV surface components.
Vaccination must begin at the ages of 12 through 26. However, vaccination in older ages is not a contraindication. At the age over 26, the vaccines protect against new infections or warts which are related to frequent and dangerous HPV-types. After the ages of 26, vaccination is usually recommended in special cases such as anal intercourse, immunosuppression or possible HIV-infection.