COVID-19 in dialysis: clinical impact, immune response, prevention and treatment

Abstract

The SARS-CoV-2 pandemic has profound adverse effects on the dialysis population. Patients requiring dialysis are at increased risk of SARS-CoV-2 infection and mortality, and many have experienced psychological distress, as well as delayed or suboptimal care. COVID-19 survivors have prolonged viral shedding, but generally develop a robust and long-lasting humoral immune response that correlates with initial disease severity. However, protection against reinfection is incomplete. A growing body of evidence reveals delayed and blunted immune responses to SARS-CoV-2 vaccination. Administration of a third dose within 1-2 months of prime-boost vaccination significantly increases antibody levels, in particular in patients with poor initial responses. Patients on dialysis have inferior immune responses to adenoviral vector vaccines than to mRNA vaccines. The immunogenicity of the mRNA-1273 vaccine is markedly better than that of the BNT162b2 vaccine, most likely by virtue of its higher mRNA content. Despite suboptimal immune responses in dialysis patients, preliminary data suggest that vaccination partially protects against infection and severe disease requiring hospitalization. However, progressive waning of immunity and emergence of SARS-CoV-2 variants with a high potential of immune escape call for a booster dose in all dialysis patients 4-6 months after prime-boost vaccination. Patients with persistent poor vaccine responses may be candidates for primary prophylaxis strategies. In the absence of specific data in dialysis patients, therapeutic strategies in the event of established COVID-19 must be extrapolated from evidence obtained in the non-dialysis population. Neutralizing monoclonal antibodies may be an attractive option after a high-risk exposure or during the early course of infection.