HPV Protection: Immunization with HPV Vaccine
In June 2006, a vaccine to prevent HPV infection was approved for use. The vaccine, Gardasil, produced by Merck Frosst, provides long-term protection against 4 types of HPV – types 16 and 18, responsible for approximately 70% of cervical cancers, and types 6 and 11, responsible for approximately 90% of genital warts. However, it is recommended that vaccinated women still have routine PAP smears performed as the vaccine does not protect against all types of HPV that cause cervical cancer.
The vaccine contains L1 protein from the outer surface of the human papillomavirus. The L1 proteins assemble into noninfectious viral-like particles – empty protein shells that do not contain genetic material. The viral-like particles are highly immunogenic in that they induce production of high levels of antibody in the host.
HPV immunization is recommended for girls 11-12 years of age, but may be given to girls as young as 9 years of age, ideally before first sexual contact and possible exposure to HPV. Once infected with one of the types of HPV included in the vaccine, disease resulting from that type of HPV will not be prevented. Catch-up immunization is also recommended in women 13-26 years of age who have not as yet been immunized.
The vaccine is given as a 3-dose series: Initial immunization2 months following initial dose6 months following intial dose
Each dose costs approximately $120 U.S. ($360 for the vaccine series).
The vaccine is safe and well-tolerated with the majority of side-effects being minor. The most common side-effect reported was pain at the injection site. Other less common side-effects included:
- syncope (fainting)