SARS-CoV-2 Vaccine Binding, Neutralizing Antibody Titers Reduced in NHL/CLL

Patients with non-Hodgkin lymphoma (NHL) or chronic lymphocytic leukemia (CLL) had substantially lower antibody binding and live-virus neutralization against SARS-CoV-2 and its variants of concern after vaccination compared with healthy vaccinees, according to a recent study.

Researchers analyzed blood from 121 patients with NHL/CLL who received two doses of the vaccine. They measured antibody binding against full-length spike protein, the receptor-binding, and N-terminal domains of the original strain and variants.

“Importantly, to our knowledge, this is the first study using a live-virus neutralization assay to show decreases in functional antibody responses against SARS-CoV-2 in patients with NHL/CLL,” the researchers wrote.

Patients with NHL/CLL had mean anti-SARS-CoV-2 spike immunoglobin G-binding titers that were 85-fold lower than healthy controls. Seroconversion occurred in only 67% of patients.

Additionally, neutralization titers were lower in patients with NHL/CLL and were correlated with binding titers (P<.0001). Neutralization titers against Delta and Omicron variants were reduced sixfold and 42-fold, respectively.

Interestingly, the researchers found that treatment with anti-CD20-directed therapies within 1 year of vaccination resulted in 136-fold lower binding titers. At 3 months from last anti-CD20-directed therapy, B-cell count of at least 4.31/µL blood around the time of vaccination predicted response (odds ratio=7.46; P=.04).

According to the researchers, these data support “the recommendations by health authorities on the need for continuing public health mitigations, additional vaccine doses, and early therapy with oral antiviral agents or passive immunization with anti-SARS-CoV-2 monoclonal antibodies to protect this highly immunosuppressed population.”

Chang A, Akhtar A, Linderman SL, et al. Humoral responses against SARS-CoV-2 and variants of concern after mRNA vaccines in patients with non-Hodgkin lymphoma and chronic lymphocytic leukemia. J Clin Oncol. 2022. doi:10.1200/JCO.22.00088