Anti-cluster of differentiation 20 (CD20) monoclonal antibody (mAb) treatment in lymphoma patients is likely to affect humoral responses to SARS-CoV-2 vaccination, although the effects on CD8 T-cell responses are uncertain. For a study, researchers sought to examine humoral and CD8 T-cell responses after two vaccinations in lymphoma patients who had received anti-CD20-mAb therapy as a single agent or in combination with chemotherapy or other anti-neoplastic agents in the previous 9 months, as well as in healthy age-matched blood donors. 

Antibodies against the receptor-binding region of the SARS-CoV-2 Spike protein were detected in seven of 110 patients three to six weeks following the second dose of immunization. Peptide-HLA multimer analysis was used to identify peripheral blood CD8 T-cell responses to common human leukocyte antigen (HLA) class I SARS-CoV-2 epitopes. Strong CD8 T-cell responses were seen in 20/29 patients (69%) and 12/16 controls (75%) samples, with similar median response magnitudes in both groups and some of the largest responses in patients. 

They found that, despite the absence of humoral immune responses in completely SARS-CoV-2-vaccinated, anti-CD20-treated lymphoma patients, their CD8 T-cell responses are comparable to controls in terms of frequency and amplitude. Current coronavirus disease 2019 (COVID-19) vaccinations are anticipated to help lymphoma patients with B-cell depleting therapy. The development of vaccines triggering T-cell responses to non-Spike epitopes might enhance protection.