key: cord-1016468-480d9pi8
authors: Khan, Awab; Cappelli, Louis; Ramdass, Vede
title: PATIENT ON RITUXIMAB CONTRACTING COVID-19 VIRUS AFTER VACCINATION
date: 2021-10-31
journal: Chest
DOI: 10.1016/j.chest.2021.07.409
sha: 353f584c0331e691b6989bea69c2c932f1e85eb4
doc_id: 1016468
cord_uid: 480d9pi8

nan

INTRODUCTION: Patients on rituximab therapy, a CD-20 monoclonal antibody, may have a blunted immune response to the COVID-19 vaccine. Our case highlights the need for clinicians and patients to recognize this and consider vaccination before initiation of therapy for more effective outcomes.

A 78-year-old female with a medical history of Non-Hodgkin Lymphoma receiving bimonthly treatments of rituximab presented with a worsening cough for two weeks. The patient was afebrile, without leukocytosis, and tachypneic at 25 breaths/min. Chest X-ray showed bilateral infiltrates. CTA of the chest was remarkable for ground-glass opacities, without evidence of thromboembolism. The patient tested positive for COVID-19 infection on arrival. The patient never had a prior COVID-19 infection. She received the COVID-19 vaccine as directed, with her last dose 10 weeks before hospital admission. The patient had been receiving rituximab therapy since her diagnosis in 2019. Of note, she received a dose of rituximab 9 days following her first dose of the COVID-19 vaccine and likely did not mount an adequate immune response to the COVID-19 vaccine since she was concurrently being treated with rituximab.

DISCUSSION: A patient being treated with a chimeric CD-20 monoclonal antibody like rituximab could decrease COVID-19 vaccine effectiveness.Rituximab is a CD-20 monoclonal antibody used in treating B-cell malignancies and autoimmune disorders. It targets the CD-20 antigen on the surface of normal and malignant B-cells. By inhibiting the cell's functionality, humoral responses to foreign antigens could be blunted.The half-life of rituximab is approximately 20.8 days. Total B-Cell depletion is observed within the first 24-72 hours after the first infusion. Complete recovery of B-cells isn't appreciated until 9-12 months following treatment. Prolonged B-cell depletion as described has been shown to decrease humoral immune response to neoantigens. Studies have shown patients undergoing CD-20 monoclonal antibody treatment have a blunted immune response to vaccination. Patients in states of B-cell depletion after rituximab therapy have already shown a decrease in response to influenza, Hib, and PPV-23 vaccination up to 10 months after the last treatment.

CONCLUSIONS: CD-20 depletion has deleterious effects on the ability to develop a humoral immune response to a vaccine. Clinicians with patients undergoing CD-20 monoclonal antibody treatments like rituximab should consider the effectiveness of vaccine administration during and soon thereafter conclusion of treatment. It should also be considered to fully vaccinate patients to the COVID-19 virus before starting Rituximab treatment.

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