ABSTRACT
Background. Patients receiving CAR-T therapy may have impaired humoral responses to SARS-CoV-2 vaccinations due to their high net state of immunosuppression associated with the underlying disease, prior lines of therapy and CAR-T treatment associated hypogammaglobinemia. Comprehensive data on vaccine immunogenicity in this patient population are currently lacking. Methods. A single-center retrospective study of adults receiving CD19 CAR-T therapy for non-Hodgkin's lymphoma was conducted between 3/27/2018 - 8/31/ 2021. Patients received at least two doses of COVID-19 vaccinations with BNT162b2 (Pfizer, BioNTech), mRNA-1273 (Moderna), or 1 dose of Ad26.COV2.S (Janssen) and had SARS-CoV-2 anti-spike (S) levels measured at least one month after the last vaccine dose. We excluded patients who received COVID-19 monoclonal antibody therapy or immunoglobulin within 3 months of the index anti-S titer. Patients were followed from the time of the first COVID-19 vaccines through their index anti-S antibody result. Patients were censored on the first day of any additional antineoplastic therapy after disease relapse. Our primary endpoint was the percentage of patients who develop a positive anti-S response (assessed by anti-S assay cutoff of >0.8 U/mL, Roche assay). Results. Twenty-five patients met eligibility. Median age was 65 years (range 41 - 78), and majority of patients were male (72%). The number of patients with a positive antibody response was 12 (48%). Median number of vaccines received was 3. 18 patients (72%) received Pfizer vaccines, 4 patients (16%) received Moderna, 2 patients (8%) received Moderna and Pfizer, and 1 patient (4%) received Janssen and Pfizer. Median anti-S titers among patients with a positive response was 111 U/mL (range 2.44 - 12500). Two patients (8%) had COVID-19, both with negative anti-S responses. Conclusion. Our analysis shows that only 48% of patients who received CAR-T therapy developed a positive antibody response after at least two COVID-19 vaccine doses, with a low median titer among responders. This patient population is at higher risk for developing severe COVID-19 disease and likely remains vulnerable even after vaccination. Alternative approaches are needed to prevent COVID-19 and mitigate disease severity in patients undergoing CAR-T.
ABSTRACT
Background. Allogeneic stem cell transplant (SCT) recipients are at an increased risk of poor outcomes from COVID-19. While the mRNA-1273 (Moderna) and BNT162b2 (Pfizer) COVID-19 mRNA vaccines are highly immunogenic in the general population, the immune response in SCT recipients is poorly understood. We characterized the immunogenicity and reactogenicity of COVID-19 mRNA vaccines in a cohort of SCT patients. Methods. We performed a prospective cohort study of 16 allogeneic SCT patients and 23 healthy controls. Blood samples for both cohorts were collected prior to first vaccination (baseline), at the time of second vaccination, and approximately 28 days post-second vaccination. Anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG levels were measured quantitatively from plasma using a multiplexed single molecule array (Simoa) immunoassay. Reactogenicity was captured for the SCT cohort via a self-reported post-vaccination diary for 7 days after each dose. Results. Demographics and SCT recipients' characteristics are shown in Table 1. In the SCT cohort, we observed a significantly lower anti-S (p< 0.0001), S1 (p< 0.0001), and RBD (p< 0.0001) IgG responses as compared to healthy controls, both at the time of dose 2 and 28 days post-vaccine series (Fig 1). Overall, 62.5% of SCT recipients were responders after vaccine series completion, as compared to 100% of healthy controls (Fig 2). While no patients had a reported history of COVID-19 diagnosis, 2 patients in the SCT cohort had elevated anti-S IgG levels and 1 showed elevated anti-N at baseline. 10/16 participants in the SCT cohort completed at least one post-vaccination diary. Local and systemic reactions were reported by 67% and 22% of participants, respectively, after dose 1, and 63% and 50% after dose 2 (Figure 3). All reported events were mild. Anti-Spike (A), anti-S1 (B), anti-RBD (C), and anti-nucleocapsid (D) IgG titers were measured at baseline, time of second dose, and approximately 28 days after second vaccination. IgG levels were measured quantitatively using multiplexed single molecule array (Simoa) immunoassays, and are reported as Normalized Average Enzymes per Bead (AEB). Allogeneic stem cell transplant recipients (mauve) showed significantly lower anti-S, S1, and RBD IgG responses as compared to healthy controls (mint). Low titers of anti-N IgG demonstrates no history of COVID-19 natural infection during the course of the study. 10 allogeneic stem cell transplant recipients completed at least one diary for 7 days after vaccination. Reactions after dose 1 are shown in light blue, and reactions after dose 2 are shown in dark blue. Local reactions (A) were reported by 67% (6/9) of participants after dose 1, and 63% (5/8) after dose 2. Systemic reactions (B) were reported by 22% (2/9) of participants after dose 1, and 50% (4/8) after dose 2. All reported events were mild (Grade 1). Conclusion. Among SCT recipients, mRNA COVID-19 vaccines were well-tolerated but less immunogenic than in healthy controls. Further study is warranted to better understand heterogeneous characteristics that may affect the immune response in order to optimize COVID-19 vaccination strategies for SCT recipients. Figure 2: Response Rate to COVID-19 Vaccination An internally validated threshold for responders was established using pre-pandemic sera from healthy adults. A positive antibody response was was defined as individuals with anti-Spike IgG levels above the 1.07 Normalized AEB threshold.
ABSTRACT
Background. Patients with lymphoid malignancies are at high risk of severe COVID-19 disease and were not included in the phase 3 mRNA vaccine trials. Many patients with lymphoid malignancies receive immunosuppressive therapies, including B-cell depleting agents, that may negatively impact humoral response to vaccination. Methods. We recruited patients with lymphoid malignancies and healthy participants who planned to receive two doses of SARS-CoV-2 mRNA vaccine (BNT162b2 or mRNA-1273). Blood was drawn at baseline, prior to second dose of vaccine, and 28 days after last vaccination. Disease characteristics and therapies were extracted from patients' electronic medical record. An ultrasensitive, single molecule array (Simoa) assay detected anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG from plasma at each timepoint. Results. 23 healthy participants and 37 patients with lymphoid malignancies were enrolled (Table 1). Low titers of anti-N (Fig 1A) demonstrate no prior exposure or acquisition of COVID-19 before vaccination or during the study. 37.8% of the lymphoid malignancy cohort responded to the vaccine, using an internally validated AEB cutoff of 1.07. A significantly higher magnitude of anti-S (p< 0.0001), anti-S1 (p< 0.0001) and anti-RBD (p< 0.0001) are present in the healthy as compared to lymphoid malignancy cohort at the second dose and day 28 post-series (Fig 1B, Fig 1C and Fig 1D). Anti-S IgG titers were compared between the healthy cohort, treatment naI&Die;ve, and treatment experienced groups (Fig 2). The treatment naI&Die;ve cohort had high titers by series completion which were not significantly different from the healthy cohort (p=0.2259), although the treatment experienced group had significantly decreased titers (p< 0.0001). Of the 20 patients who had received CD20 therapy, there was no clear correlation of anti-S IgG response with time from CD20 therapy, although most patients who received CD20 therapies within 12 months from the vaccine had no response (Figure 3). Conclusion. The vaccine-induced immune response was poor among treatment-experienced patients with lymphoid malignancies, especially among those who received CD20 therapies within 12 months.