Suboptimal response to COVID-19 mRNA vaccines in hematologic malignancies patients

Abstract

Studies describing SARS-CoV-2 immune responses following mRNA vaccination in hematology malignancy (HM) patients are virtually non-existent. We measured SARS-CoV-2 IgG production in 67 HM patients who received 2 mRNA vaccine doses. We found that 46% of HM patients did not produce antibodies and were therefore vaccine non-responders. Patients with B-cell CLL were at a particularly high risk, as only 23% had detectable antibodies despite the fact that nearly 70% of these patients were not undergoing cancer therapy. HM patients should be counseled about the ongoing risk of COVID-19 despite vaccination. Routine measurement of post-vaccine antibodies in HM patients should be considered. Novel strategies are needed to prevent COVID-19 in these individuals.

Figure 1.. Extinction coefficient (signal/cutoff) ratios of SARS-CoV-2 Spike IgG stratified by vaccine responders (1A) and non-responders (1B), based on whether they had chronic lymphocytic leukemia (CLL) or other hematological malignancies.

* Comparisons between CLL versus non-CLL patients. Extinction coefficient ratios for the 4 patients with other myeloid malignancies were not available. Solid lines indicate medians.