Trial Information

Duration of Human Papilloma Virus (HPV) Type-Specific Antibody After Administration of Quadrivalent HPV Vaccine (QHPV) to HIV-1 Infected Children Previously Enrolled in IMPAACT P1047

Genital Human Papilloma Virus (HPV) infection is the most common sexually transmitted
infection (STI) in the United States and worldwide. Over 50% of sexually active adolescents
will become infected with HPV. HPV infection is strongly associated with the development of
anogenital dysplasias and invasive cancers. Because HPV is a STI, optimal prevention in
women will depend on prevention in their partners as well. Males remain a significant
reservoir of HPV and vaccinating them will be essential for rapidly preventing transmission
of HPV in the community.

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(manufacturer's data, unpublished), but there is no such information available from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.

We seek to determine the long-term durability and kinetics of the vaccine-induced
HPV-type-specific antibody and CMI responses in HIV-infected children that were, and are
being, immunized in P1047. These subjects are a unique cohort that will allow us to
approach this specific clinical issue.