P1085 is a sub study of P1047, which investigated the safety and immunogenicity of Quadrivalent HPV (QHPV) in HIV-infected girls and boys, age 7 to <12 years of age. This study was a placebo-controlled trial that compared a recommended three dose schedule of QHPV in one study arm (Arm A) with an arm that received placebo (Arm B). P1047 has thus far demonstrated that QHPV can be safely administered to human immunodeficiency virus (HIV)-infected boys and girls and will stimulate seroconversion in more than 95% of vaccinees. However, these antibody levels were 30-50% lower than those achieved in children without HIV infection. Since levels of vaccine-induced antibodies decline with time after vaccination, it is uncertain if vaccine-induced immunity will be life-long. This concern is supported by some evidence that naturally acquired HPV-specific antibody might decline to a level that will permit re-infection. Comparative persistence data for HPV-specific antibody is available for 5-6 years after vaccination of almost 1000 children without HIV infection (manufacturer's data, unpublished), but there is no such information available from HIV-infected vaccinees.