Immune Responses to Pneumococcal Vaccination Among HIV-infected Subjects

The purpose of this study is to evaluate the best timing for administering pneumococcal vaccine (PV) to HIV-infected adults that have CD4 cell counts of more than 200 and are not yet receiving combination antiretroviral treatment (ART). Participants in this study will be assigned by chance to receive vaccination with PV prior to starting ART or after at least 6 months of ART. Antibody levels to components of the PV will be measured at 6 months and 12 months after vaccination. The results will tell us if patients that receive PV after 6 months of ART have better response to the vaccine than those that get vaccinated prior to treatment.

Arm 1 will receive PV (23-valent pneumococcal polysaccharide vaccine) prior to starting antiretroviral treatment and will receive PLACEBO after at least 6 months of starting antiretroviral treatment. PV (23-valent pneumococcal polysaccharide vaccine): Currently commercially available pneumococcal polysaccharide vaccine

Arm 2 will receive PLACEBO prior to starting antiretroviral treatment and will receive PV (23-valent pneumococcal polysaccharide vaccine) after at least 6 months of starting antiretroviral treatment. PV (23-valent pneumococcal polysaccharide vaccine): Currently commercially available pneumococcal polysaccharide vaccine

Immunoglobulins are antibodies or special proteins that the immune system produces to protect the body against infections. IgG is the most common antibody. We measure baseline levels (before the vaccine is administered) to know how much antibody the subject has at the start point to be able to evaluate how much antibody is produced after the vaccine is administered.

Immunoglobulins are antibodies or special proteins that the immune system produces to protect the body against infections. IgG is the most common antibody. This point of time (one-month after vaccine), gives the information about how much antibody was produced by the participant's immune system in response to the vaccine.

Immunoglobulins are antibodies or special proteins that the immune system produces to protect the body against infections. IgM is the first antibody produced by the immune system to fight a new infection. We measure baseline levels (before the vaccine is administered) to know how much antibody the subject has at the start point to be able to evaluate how much antibody is produced after the vaccine is administered.

Immunoglobulins are antibodies or special proteins that the immune system produces to protect the body against infections. IgM is the first antibody produced by the immune system to fight a new infection. This point of time (one-month after vaccine), gives the information about how much antibody was produced by the participant's immune system in response to the vaccine.

This assay helps us to know how the antibody produced by the body are working to kill the bacteria against which the antibody is produced. As explained previously for the immunoglobulins' assays, we measure the baseline point to be able to determine the increase after the vaccine is administered.

This assay helps us to know how the antibody produced by the body are working to kill the bacteria against which the antibody is produced. This point of time (one-month after vaccine), gives the information about how much the killing activity increased 1 month after the vaccine was administered.

Inclusion Criteria: HIV infected CD4 count >200 no acute illness no pneumococcal vaccination within 3 years naive to treatment or if previously on treatment, no antiretroviral treatment for at least 6 months willingness to start antiretroviral treatment as recommended by current guidelines Exclusion Criteria: prior pneumococcal vaccination within 3 years prior AIDS diagnosis based on opportunistic disease acute illness