Immunogenicity and reactogenicity of yellow fever vaccine in people living with HIV.

Abstract

To evaluate immunogenicity and reactogenicity of Yellow Fever (YF) vaccine in people living with HIV (PLWH) compared to HIV-uninfected controls. In this longitudinal interventional trial (NCT03132311), PLWH with CD4 ≥200 cells/μL and controls, aged 18-59, without a previous history of YF vaccination received a single standard dose of YF vaccine (17DD) and were followed at Days 5, 30 and Year 1. YF-neutralization titers were measured at Days 0, 30 and Year 1 and geometric mean titers (GMT) were calculated. Adverse events (AE) and YF virus detection were measured at Days 5 and 30. Linear regression evaluated factors associated with YF-neutralization titers. 218 PLWH and 82 controls were included. At baseline, all PLWH were using antiretroviral therapy; 92.6% had undetectable HIV viral load (VL) and median CD4 was 630 cells/μL (IQR 463-888). YF vaccine was safe and there were no serious AEs. At Day 30, seroconversion was observed in 98.6% of PLWH (95%CI: 95.6-99.6) and in 100% of controls (95%CI: 93.9-100); at Year 1, 94.0% of PLWH (95% CI: 89.6-96.7) and 98.4% of controls (95%CI 90.3-99.9) were seropositive. PLWH had lower GMTs than controls at Day 30 and Year 1. Baseline VL >1,000 copies/mL, low CD4 counts and low CD4/CD8 ratio were associated with lower YF-neutralization titers. YF vaccine is safe in PLWH with CD4 ≥ 200 cells/μL. YF vaccine immunogenicity is impaired in PLWH, particularly among those with high VL, low CD4 counts and low CD4/CD8 ratio at vaccination and YF-neutralization titers decays over time.