Immunogenicity of the 13-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine in people living with HIV on combination antiretroviral therapy

Abstract

People living with HIV (PLWH) are at increased risk of pneumococcal infections compared with the general population. The objective of this study was to investigate the immunogenicity of the combined pneumococcal vaccination schedule in PLWH. In this prospective cohort study, adult PLWH on antiretroviral therapy and HIV-negative controls received the 13-valent pneumococcal conjugate vaccine (PCV13) at baseline followed by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) at Month 2. Serotype-specific IgG levels of 24 vaccine serotypes were measured at Months 0, 2, 4, 6 and 12. The primary outcome was seroprotection at Month 4, defined as the proportion of patients with a post-immunisation IgG concentration of ≥1.3 μg/mL for ≥70% (17/24) of vaccine serotypes. Samples of 120 patients were analysed. Seroprotection at Month 4 was 49% (39/80) for PLWH and 82% (28/34) in controls. At Month 12, seroprotection had decreased to 23% (18/79) and 63% (22/35), respectively. Nadir CD4 count ≥200 cells/mm³, preserved kidney function and co-administration of the diphtheria-tetanus-polio (DTP) vaccine were associated with better seroprotection among PLWH. IgG levels both of PLWH and controls (all 24 vaccine serotypes) were significantly higher compared with baseline at all timepoints. Although IgG levels of all 24 vaccine serotypes increased significantly both in PLWH and controls, only a minority of PLWH achieved seroprotection after PCV13 followed by PPSV23. In addition, protective immunity waned rapidly. Further research into alternative vaccinations strategies for PLWH is needed, such as vaccination schedules with higher-valent pneumococcal vaccines. The DTP vaccine may augment pneumococcal vaccination responses.

Keywords: HIV; Immunogenicity; Pneumococcal disease; Pneumococcal vaccination; Vaccine.