Background. The risk of pneumococcal disease persists, and antibody responses to revaccination with the 23-valent polysaccharide vaccine (PPV) are low among human immunodeficiency virus (HIV) - infected adults. We determined whether revaccination with the 7-valent pneumococcal conjugate vaccine (PCV) would enhance these responses. Methods. In a randomized clinical trial, we compared the immunogenicity of revaccination with PCV (n=131) or PPV (n=73) among HIV-infected adults (median CD4 cell count, 533 cells/mm3) who had been vaccinated with PPV 3-8 years earlier. HIV-uninfected adults (n=25) without prior pneumococcal vaccination received 1 dose of PCV. A positive response was defined as a ≥2-fold increase (from baseline to day 60) in capsule-specific immunoglobulin G, with a postvaccination level ≥1000 ng/mL for at least 2 of the 4 serotypes. Results. HIV-infected persons demonstrated a higher frequency of positive antibody responses to PCV than to PPV (57% vs 36%) (P=.004) and greater mean changes in the immunoglobulin G concentration from baseline to day 60 for serotypes 4, 9V, and 19F (P<.05, for all), but not for serotype 14. However, by day 180, both outcomes were similar. Responses to PCV were greater in frequency and magnitude for all serotypes in HIV-uninfected adults, compared with those in HIV-infected adults. Conclusions. Among persons with HIV infection, revaccination with PCV was only transiently more immunogenic than PPV, and responses were inferior to those in HIV-uninfected subjects with primary vaccination. Pneumococcal vaccines with more robust and sustained immunogenicity are needed for HIV-infected adults. Clinical trial registration. ClinicalTrials.gov identifier NCT00622843.
Bibliographical noteFunding Information:
Financial support: The Infectious Disease Clinical Research Program (grant IDCRP RV150), a Department of Defense program executed through the Uniformed Services University of the Health Sciences. This project has been funded in whole, or in part, with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health (under interagency agreement Y1-AI-5072). Additional support was obtained from the Veterans Affairs Research Service.