Posted: Friday, May 6, 2022
In patients with chronic lymphocytic leukemia (CLL) in Israel, the Pfizer-BioNTech mRNA COVID-19 vaccine (known as BNT162b2) is safe but far less effective than it is in immunocompetent individuals, according to research published in Haematologica. Tamar Tadmor, MD, of Bnai Zion Medical Center in Haifa, Israel, and colleagues found that of 373 study participants with CLL whose antibody response to the vaccine could be properly analyzed, an antibody response could be detected in 43% of the cohort, overall, following the second dose.
Based on factors that the study authors found to influence the response of subgroups to the vaccine, they developed a straightforward score compilation to help predict whether a given individual with CLL will develop a sufficient response to the BNT162b2 vaccine. The seven key factors follow: immunoglobulin (Ig) G, IgA, IgM, and hemoglobin levels (the closer to normal the levels, the more likely the response); age (those younger than 70 were more likely to develop antibodies); treatment status (treatment-naive patients generally responded better); and the timing of any treatment with an anti-CD20 antibody (such treatment far reduced the chance of response).
Specifically, of these 373 patients with CLL who had been treated at nine medical centers in Israel, “61% of the treatment-naive patients responded to the vaccine, [whereas] responses developed in only 18% of those with ongoing disease, 37% of those previously treated with a BTK inhibitor, and 5% of those given an anti-CD20 antibody…in the 12 months preceding vaccination,” noted the team. Further, among patients treated with a BCL2 inhibitor as monotherapy or in combination with an anti-CD20 antibody, 62% and 14%, respectively, developed an immune response.
“There was a high concordance between neutralizing antibodies and positive serological response to spike protein,” Dr. Tadmor and co-investigators found. Conversely, neither gender nor IGHV mutation status was a statistically significant factor in predicting response in their cohort.
Disclosure: The study authors reported no conflicts of interest.