Evaluation of Antibody Responses in Patients with B-Cell Malignancies after Two and Three Doses of Anti-SARS-CoV-2 S Vaccination-A Retrospective Cohort Study

Patients with B-cell malignancies are at a higher risk of severe SARS-CoV-2 infections. Nevertheless, extensive data on the immune responses of hematological patients and the efficacy of the third dose of the vaccine are scarce. The goal of this study was to determine standardized anti-SARS-CoV-2 S antibody levels and to evaluate differences between treatment modalities in response to the second and third vaccines among patients with B-cell malignancies treated at the University Hospital Krems and the University Hospital of Vienna. The antibody levels of a total of 80 patients were retrospectively analyzed. The results indicate a significant increase in antibody production in response to the third vaccination. The highest increases could be observed in patients in a "watchful-waiting" and "off-therapy" setting. Encouragingly, approximately one-third of patients who did not develop antibodies in response to two vaccinations achieved seroconversion after the third vaccination. "Watchful-waiting", "off-therapy" and treatment with BTK inhibitors were indicative for increased antibody response after the third dose compared to anti-CD19 CAR T-cell and anti-CD-20 antibody treatment. In summary, the results of this study underline the pre-eminent role of the need for complete vaccination with three doses for the development of protective immunity in patients with B-cell malignancies.

Evaluation of Antibody Responses to COVID-19 Vaccines among Solid Tumor and Hematologic Patients

Simple Summary

Vaccination is the primary public health strategy to cope with the COVID-19 pandemic. Although solid tumor and hematologic patients are at higher risk of serious COVID-19-related complications and mortality, data on immune responses to COVID-19 vaccines in this patient cohort are particularly scarce. Our results show that antibody titers against the SARS-CoV-2 spike protein are significantly higher in solid tumor vs. hematologic patients. While SARS-CoV-2 antibody titers were equal among sexes, an age-dependent decrease could be observed. Of note, our studies additionally show that complete vaccination represents a valuable predictor for high anti-SARS-CoV-2 antibody responses in solid tumor and hematologic patients. Our findings aim to support future vaccination strategies in these highly vulnerable patients, including vaccination booster programs and alternative protective approaches.

Abstract

Vaccination is the primary public health strategy to cope with the COVID-19 pandemic. Although solid tumor and hematologic patients are at higher risk of serious COVID-19-related complications, data on immune responses to COVID-19 vaccines in this patient cohort are particularly scarce. The present study, therefore, aimed at the standardized determination of anti-SARS-CoV-2 spike protein antibody titers among non-vaccinated versus vaccinated solid tumor and hematologic patients who are under clinical observation or under treatment at the University Hospital Krems. Standardized anti-SARS-CoV-2 S antibody titers of a total of 441 patients were retrospectively analyzed. Our results show that antibody titers against the SARS-CoV-2 spike protein are significantly higher in solid tumor versus hematologic patients. While SARS-CoV-2 antibody titers were equal among sexes, an age-dependent decrease was observed. Of note, our studies additionally show that complete vaccination represents a valuable predictor for high anti-SARS-CoV-2 antibody responses in solid tumor and hematologic patients. In summary, to date, this is one of the largest studies to comprehensively evaluate the impact of various COVID-19 vaccines on anti-SARS-CoV-2 S antibody production in solid tumor and hematologic patients. Our findings aim to support future vaccination strategies in these highly vulnerable patients, including vaccination booster programs and alternative protective approaches.