Background: Chronic lymphocytic leukemia (CLL) and other Non-Hodgkin’s lymphomas (NHLs) are associated with broad immunosuppression, conferring a greater risk for infection-related morbidity and mortality. During the SARS-CoV-2 pandemic, patients with these conditions have been shown to be more susceptible to severe cases of infection. Vaccination against SARS-CoV-2 generally protects against severe disease, but there is scarce data on immune response in those with lymphoid malignancies. Our study aims to analyze antibody (Ab) response to vaccination against SARS-CoV-2 in patients with CLL, Waldenstrom macroglobulinemia (WM) and other NHLs. Methods: 398 patients with lymphoid malignancies seen between January and October 2021 were screened for eligibility. Ab titers using the Access SAR-COV-2 assay developed by Beckman Coulter Inc were obtained after the completion of a vaccination series with Pfizer (n=146), Moderna (n=90), Johnson & Johnson (n=1) or multiple brands (n=3). A response was defined as a positive total Ab or spike protein Ab. Groups were compared using chi-square tests, and a p-value of < 0.05 was statistically significant. Results: 240 patients with post-vaccination SARS-CoV-2 Ab results were included. Ab response was 50% in CLL, 67% in WM, and 71% in the remaining NHLs. In the CLL cohort (n=181), current or prior cancer therapy at any time led to a lower rate of positive Ab’s compared to treatment-naïve patients (36% vs. 68%; p=0.000019), and response was particularly low in patients who had received anti-CD20 immunotherapy at any time (28% vs. 61%; p=0.000032). There was a trend towards lower Ab response in patients who received anti-CD20 agents within a year from vaccination compared to those who had these therapies more than one year prior (20% vs. 37%; p=0.14). For CLL patients, there was a significant difference in Ab response when receiving the Moderna series (61%) compared to Pfizer (44%) (p=0.028). More information is summarized in Table 1. Conclusions: This study provides data from a large cohort of patients with CLL and other NHLs on Ab response to SARS-CoV-2 vaccination. Active or prior therapy for CLL was associated with lower rates of Ab response to vaccination, especially when treated with anti-CD20 therapy, which is consistent with prior publications. However, we also found a significant increase in Ab response rates after Moderna SARS-CoV-2 vaccination in treated CLL patients compared to other vaccination series.
CLO22-043 Table 1: Antibody Response Rate in CLL, WM and Other NHL after SARS-CoV-2 Vaccination
*Comparing antibody positivity in respective subgroups among patient who received either the Moderna or Pfizer vaccination. P-value calculated using chi-square testing and a value of < 0.05 is considered statistically significant.
** Some patients excluded from subsequent p-value calculation due to receiving doses from different vaccine brands
†Denotes current or prior therapy with specified CLL therapy and antibody response to vaccination. Some patients are included in multiple rows due to receiving multiple classes of treatment.
Ab, antibody; BCL-2, B-cell lymphoma 2; BTK, Bruton tyrosine kinase; CLL, chronic lymphocytic leukemia; NHLs, non-Hodgkin’s lymphomas; WM, Waldenstrom macroglobulinemia