Impaired booster-induced SARS-CoV-2 antibody responses in rituximab-treated B-cell lymphoma patients despite peripheral B-Cell Recovery

Jurca, Tomaž (author), Boltežar, Lučka (author), Oražem, Miha (author), Fujs Komloš, Kristina (author), Pohar, Katka (author), Jevnikar, Sara (author), Poljak, Mario (author), Mlakar-Mastnak, Denis (author), Rotovnik-Kozjek, Nada (author), Vratanar, Bor (author), Ocvirk, Janja (author), Ihan, Alojz (author)

Rituximab-treated patients with B-cell lymphoma exhibit profound B-cell depletion and impaired vaccine-induced antibody responses. However, it remains uncertain whether recovery of peripheral B-cell counts after rituximab is sufficient to restore effective humoral immunity following booster vaccination. Patients and methods In this prospective, single-center observational study at the Institute of Oncology Ljubljana, adult B-cell lymphoma patients treated with or previously exposed to rituximab received the Comirnaty® mRNA COVID-19 vaccine. Antibody responses to the SARS-CoV-2 spike and nucleoprotein were measured at baseline, 14 days after the second dose, and at 3, 6, 9, and 12 months. A third dose was administered at 6 months. T-cell responses (IFN-γ release) were assessed in patients before and after the primary series and booster dose. Lymphocyte subsets were analysed pre-vaccination. Adverse events and nutritional status were monitored. Results Patients undergoing anti-CD20 therapy showed absent antibody responses. Longer intervals since rituximab correlated with peripheral B-cell repopulation. However, even after reaching normal B-cell counts, patients’ antibody responses after revaccination remained significantly lower than in controls. Conclusions Rituximab is associated with impaired vaccine-induced antibody responses. Despite recovery of peripheral B-cell counts, patients with B-cell lymphoma show reduced humoral responses compared with healthy individuals following booster COVID-19 vaccination.

• Language: English
• Keywords: lymphoma, B-cell, rituximab, COVID-19 vaccines
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: Str. 76-85
• Numbering: Vol. 60, no. 1
• PID: 20.500.12556/RUL-185261
• UDC: 616-006
• ISSN on article: 1318-2099
• COBISS.SI-ID: 276354563
• Publication date in RUL: 30.07.2026

Record is a part of a journal

• Title: Radiology and oncology
• Shortened title: Radiol. oncol.
• Publisher: Association of Radiology and Oncology
• ISSN: 1318-2099
• COBISS.SI-ID: 32649472

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: limfom, B-celični limfom, rituksimab, cepljenje proti covid-19

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P3-0083
• Name: Odnosi parazitskega obstajanja

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P3-0321
• Name: Napovedni dejavniki poteka bolezni in odgovora na zdravljenje pri različnih vrstah raka