Gardasil

Quadrivalent human papillomavirus (Types 6, 11, 16, 18) recombinant vaccine

MERCK

Vaccine approved for the prevention of cervical cancer

Efficacy. The efficacy of the HPV vaccine was evaluated in 4 studies enrolling a combined 20,541 women aged 16 to 26 years. Patients received vaccine or placebo on the day of enrollment and 2 and 6 months thereafter. Primary efficacy analyses were conducted in the per-protocol efficacy population, consisting of individuals who received all 3 vaccinations within 1 year of enrollment, did not have major deviations from study protocol, and were naïve (polymerase chain reaction [PCR]-negative in cervicovaginal specimens and seronegative) to the relevant HVP types prior to dose 1 and through 1 month post-dose 3 (Month 7). Efficacy was measured after the Month 7 visit. In subjects who were naïve to all 4 vaccine HPV types, CIN, genital warts, VIN, and VaIN caused by any of the 4 vaccine HPV types were counted as end points. Among subjects who were positive for a vaccine HPV type at Day 1, end points related to that type were not included in the analyses of prophylactic efficacy. End points related to the remaining types for which the subject was naïve were counted. The vaccine was efficacious against HPV disease caused by each of the 4 vaccine HPV types. In a pre-defined analysis of patients naïve to all vaccine HPV types, the efficacy of the vaccine against HPV 16/18-related disease was 100% (95% CI, 87.9%–100.0%) for CIN 3 or AIS and 100% (95% CI, 55.5%–100.0%) for VIN 2/3 or VaIN 2/3. The efficacy of the vaccine against HPV 6-, 11-, 16-, and 18-related VIN 1 or VaIN 1 was 100% (95% CI, 75.8%–100.0%). Likewise, individuals who were already infected with 1 or more vaccine-related HPV types prior to vaccination were protected from clinical disease caused by the remaining vaccine HPV types.

Safety. As with any vaccine, vaccination with the HPV vaccine may not result in protection in all recipients. The HPV vaccine is not intended to be used for the treatment of active genital warts; cervical cancer; CIN, VIN, or VaIN. The HPV vaccine has not demonstrated prophylactic efficacy against diseases caused by non-vaccine HPV types. As with all injectable vaccines, appropriate medical treatment should always be readily available in case of rare anaphylactic reactions following the administration of the vaccine. Individuals with impaired immune responsiveness, whether due to the use of immunosuppressive therapy, a genetic defect, Human Immunodeficiency Virus (HIV) infection, or other causes, may have reduced antibody response to active immunization. As with other intramuscular injections, the HPV vaccine should not be administered to individuals with bleeding disorders such as hemophilia or thrombocytopenia, or to persons on anticoagulant therapy unless the potential benefits clearly outweigh the risk of administration. The HPV vaccine is not recommended for use in pregnant women. The most commonly reported adverse events associated with the HPV vaccine include injection-site reactions (ie, pain, swelling, erythema, pruritus), pyrexia, vomiting, malaise, arthralgia, insomnia, and nasal congestion.

Dosing. The HPV vaccine should be administered intramuscularly as 3 separate 0.5-mL doses, with the first dose occurring on the elected date and the 2 subsequent doses following at 2 and 6 months after the first dose, respectively. Injections should be administered in the deltoid region of the upper arm or in the higher anterolateral area of the thigh.