Objective: Immunocompromised individuals are at an increased risk of pneumococcal disease. Vaccination is recommended as an important strategy to reduce risk of pneumococcal disease in HIV-infected individuals. This study evaluated the safety and immunogenicity of three 13-valent pneumococcal conjugate vaccine (PCV13) doses followed by one dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23) at 1-month intervals in pneumococcal vaccine-naive, HIV-infected individuals.
Design: This was a phase 3, open-label, single-arm study.
Methods: Pneumococcal vaccine-naive, HIV-infected individuals at least 6 years of age with CD4 T-cell count at least 200 cells/μl and viral load less than 50 000 copies/ml received three doses of PCV13 followed by one dose of PPSV23 at 1-month intervals. Serotype-specific antipneumococcal immune responses were assessed by IgG geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) assay geometric mean titres (GMTs) after each dose. Local reactions at the PCV13 injection site, systemic and other adverse events were collected.
Results: Three hundred and one individuals were enrolled and vaccinated; 279 completed the study. Statistically significant increases in IgG GMCs and OPA GMTs were observed for all serotypes after dose 1 of PCV13 compared with prevaccine levels. GMCs and GMTs were comparable or only modestly increased for all serotypes after PCV13 doses 2 and 3 and after PPSV23. The majority of local reactions and systemic events were mild to moderate in severity.
Conclusion: A three-dose regimen of PCV13 was well tolerated in pneumococcal vaccine-naive, HIV-infected individuals. Significant immune responses to all serotypes were observed following the first dose of PCV13, with only modest increases in antibody titres following subsequent PCV13 or PPSV23 administration.
Trial registration: ClinicalTrials.gov NCT00962780.