Immune Response to Pneumococcal Vaccination in Aging HIV Positive Adults

The purpose of this study is to learn more about how older people with HIV respond to the pneumococcal or pneumonia vaccine. Pneumonia occurs very frequently in in older persons AND in persons who are infected with HIV. Therefore, it is common practice to vaccinate against pneumonia in these patient populations. Because older patients with HIV fit both of these categories, it is believed that they are at an increased risk of pneumonia.

There are two types of pneumonia vaccines available for adults approved by the Federal Drug Administration (FDA). One is called the pneumococcal polysaccharide vaccine (PPV23) and protects against 23 different strains of the pneumonia bacteria. The other type of vaccine called the pneumococcal conjugate vaccine (PCV13) protects against different strains of the pneumonia bacteria.

Until 2012, it was recommended that all HIV-positive adults receive PPV23 when diagnosed with HIV and again 5 years later. More recently, the guidelines have changed to all HIV-positive adults are to receive PCV13, followed later with PPV23. At this point in time, it is not clear which regimen works better in aging HIV positive adults. Investigators are doing this study to compare the effectiveness of each vaccine regimen in aging HIV positive adults compared to healthy adults. Although several studies show short-term efficacy or increased antibody response in HIV+ persons with this vaccine, others do not, in either HIV+ population or in elderly. Large efficacy trials necessary to establish clinical superiority of PCV compared to PPV will likely not be conducted, particularly in the aging HIV+ population. It is therefore essential to define immune responses to conjugated and free-polysaccharide preparations by examining traditional antibody and functional levels as well as B cell subsets, critically affected by aging and HIV. Will either PCV or PPV elicit an immune response compatible with protection in this population? Based on persistent B cell perturbations in HAART-treated persons, it is hypothesized that immunization of aging HIV+ persons with PPV23 will be as effective as a PCV13 containing regimen on a quantitative, qualitative, B and T cell level and that the magnitude of this response will be related to the degree of chronic inflammation. The proposed studies are highly significant as they will define the B and T cell responses to a TI-2 and T-cell dependent form of pneumococcal vaccine in the aging HIV+ population. These data will provide the necessary basis for development of a rational vaccination approach, including the potential use of novel adjuvant. In this study the investigators will:

1. Test the hypothesis that vaccination with either PPV alone (TI-2) or a PCV containing regimen (TD) results in similar antibody levels/functional activity, that are determined by levels of chronic inflammation in aging HIV+. The investigators will immunize the study group HIV+ persons 50-65 and controls (HIV+21-40 and HIV- 50-65 years) with PCV13 followed by PPV23 and HIV+ 50-65 and HIV- 50-65 with PPV alone. The investigators will examine immune responses to pneumococcal polysaccharides (PPS) 23 (F), 14, 3, 7 (F) and 19 (A) on a quantitative and qualitative level using ELISA and opsonophagocytic assays (OPA) and correlate the response to the degree of inflammation measured in each participant.

2. To test the hypothesis that the levels of antigen specific B cells identified with PPS will be comparable between the PPV and PCV vaccine recipients. Pre- and post-immunization peripheral blood samples will be obtained. Extensive phenotype analysis using antibodies against cluster of differentiation (CD)19, 20, 21, 27, 38, 40, immunoglobulin M (IgM) , B-cell activating factor (BAFF), trans-membrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antigen (BCMA) markers will be used to characterize PPS-labeled B cells. Specific phenotypes will be correlated with antibody levels, OPA and inflammatory markers and compared to the control populations immunized with PPV.