Hepatitis B Vaccine Genetics: A Substudy of ATN 024 and ATN 025

All subjects who are currently enrolled or have completed ATN 024 or ATN 025 are eligible for participation on this substudy with the exception of those who were discontinued from ATN 024 or ATN 025 prior to completing the first post-vaccination serology (week 28) visit.

Participants in ATN 024 are HIV-infected youths aged 12 to 24 years, while participants in ATN 025 are HIV-uninfected youths aged 12 to17 years, thus participants in this substudy will be HIV-infected and uninfected youth aged 12 to 24 years. All eligible youths must be negative for HBV core antibody, HBV surface antigen, and HBV surface antibody at the time of enrollment in to the parent protocols.

Inclusion Criteria:

• Subjects currently enrolled in ATN 024 or ATN 025 are eligible for enrollment in ATN 052 beginning at or following completion of the week 28 visit.
• Subjects previously enrolled in ATN 024 or ATN 025 are eligible for enrollment in ATN 052, unless the subject was prematurely discontinued from the study prior to the first post-vaccination serology assessment which is performed at week 28.
• Current pregnancy is permitted.
• A signed informed assent/consent must be obtained from the subject.
• Written parental or guardian permission must be obtained where required by the institutional review board/ethics committee (IRB/EC).

Exclusion Criteria:

• Inadequate post-vaccination serology evaluation in ATN 024 or ATN 025.
• Unable to obtain informed consent and/or parental/legal guardian permission where required by the local IRB/EC.