Immune System Function Following Vaccination in HIV Infected Children Taking Anti-HIV Drugs

Inclusion Criteria: * Completed the 96-week initial study period of PACTG P1024 and had enrolled into that study between June 1, 2001 and March 31, 2002 * Fulfilled PACTG P1024's definition of HAART (taking 3 or more antiretrovirals \[ARVs\] from at least 2 of the available therapeutic drug classes) during PACTG P1024's vaccination period (Weeks 0 to 24). Patients who were taking 3 nucleoside reverse transcriptase inhibitors during that period without a non-nucleoside reverse transcriptase inhibitor or a protease inhibitor (PI) are not eligible for this study. Nontherapeutic boosting doses of ritonavir used in ritonavir-boosted PI regimens are not counted as separate ARVs. * Stable ARV regimen in the 4 weeks prior to study entry * No changes anticipated to current ARV regimen during this study * Willing to complete all study vaccinations and evaluations * Willing to use acceptable forms of contraception, if applicable * Parent or guardian willing to provide informed consent, if applicable Exclusion Criteria: * Abnormal blood or chemistry values on most recent laboratory tests. More information on this criterion can be found in the protocol. * Received PCV, HBV, PPV, or MMR vaccines during PACTG P1024 in a sequence other than specified in PACTG P1024 * Received one or more doses of each of PCV, PPV, MMR, or HBV vaccines since the end of PACTG P1024's vaccination period * Previous Grade 3 or higher adverse events or allergic reactions judged to be possibly or definitely rela…