Impact of Moderna mRNA-1273 Booster Vaccine on Fully Vaccinated High-Risk Chronic Dialysis Patients after Loss of Humoral Response.

The long-term effect of protection by two doses of SARS-CoV-2 vaccination in patients receiving chronic intermittent hemodialysis (CIHD) is an urging question. We investigated the humoral and cellular immune response of 42 CIHD patients who had received two doses of SARS-CoV-2 vaccine, and again after a booster vaccine with mRNA-1273 six months later. We measured antibody levels and SARS-CoV-2-specific surrogate neutralizing antibodies (SNA). Functional T cell immune response to vaccination was assessed by quantifying interferon-γ (IFN-γ) and IL-2 secreting T cells specific for SARS-CoV-2 using an ELISpot assay. Our data reveal a moderate immune response after the second dose of vaccination, with significantly decreasing SARS-CoV-2-specific antibody levels and less than half of the study group showed neutralizing antibodies six months afterwards. Booster vaccines increased the humoral response dramatically and led to a response rate of 89.2% for antibody levels and a response rate of 94.6% for SNA. Measurement in a no response/low response (NR/LR) subgroup of our cohort, which differed from the whole group in age and rate of immunosuppressive drugs, indicated failure of a corresponding T cell response after the booster vaccine. We strongly argue in favor of a regular testing of surrogate neutralizing antibodies and consecutive booster vaccinations for CIHD patients to provide a stronger and persistent immunity.

High overall mortality of Mycobacterium genavense infections and impact of antimycobacterial therapy: Systematic review and individual patient data meta-analysis.

INTRODUCTION: Mycobacterium genavense is a fastidious slow growing mycobacterium (SGM) that causes disseminated infections in immunocompromised hosts. It has been described in HIV-positive individuals and increasingly in patients without HIV. The infections are difficult to treat and the optimal antimycobacterial regimen is still unknown. METHODS: An individual patient data meta-analysis was conducted aiming at including all hitherto published cases of infection with M. genavense. Clinical manifestations, microbiological data, dispositions and immunosuppression were recorded. Antimycobacterial therapies and mortality were analyzed by logistic regression and time-to-event analysis. RESULTS: We included 223 patients with infection due to M. genavense published from 1992 to 2021. While the majority was HIV positive (n = 171, 76.7%), 52 patients were non-HIV-patients (23.3%), 36 of whom received immunosuppressive therapy (69%). We could confirm the bacterium's tropism for the gastrointestinal tract with abdominal pain, hepato-/splenomegaly and abdominal lymphadenopathy being major clinical manifestations. More than 90% of patients received antimycobacterial therapy. The regimens consisted mainly of macrolides, rifamycins and ethambutol. Overall mortality was high, but in logistic regression and time-to-event analysis a macrolide containing regimen was associated with better outcomes. CONCLUSION: In this first individual patient data meta-analysis of infections with M. genavense we confirm its tropism for the gastrointestinal tract. The high overall mortality underlines the clinical relevance of infection with this bacterium for the individual patient. In addition, our data give a hint that a macrolide containing regimen is associated with better survival.