Characteristics of patients with hematologic malignancies without seroconversion post-COVID-19 third vaccine dosing.

Objectives: The objective of this study is to explore the characteristics of the subset of patients with hematologic malignancies (HMs) who had little to no change in SARS-CoV-2 spike antibody index value levels after a third mRNA vaccine dose (3V) and to compare the cohort of patients who did and did not seroconvert post-3V to get a better understanding of the demographics and potential drivers of serostatus. Study design: This retrospective cohort study analyzed SARS-CoV-2 spike IgG antibody index values pre and post the 3V data on 625 patients diagnosed with HM across a large Midwestern United States healthcare system between 31 October 2019 and 31 January 2022. Methods: To assess the association between individual characteristics and seroconversion status, patients were placed into two groups based on IgG antibody status pre and post the 3V dose, (-/+) and (-/-). Odds ratios were used as measures of association for all categorical variables. Logistic regressions were used to measure the association between HM condition and seroconversion. Results: HM diagnosis was significantly associated with seroconversion status (P = 0.0003) with patients non-Hodgkin lymphoma six times the odds of not seroconverting compared with multiple myeloma patients (P = 0.0010). Among the participants who were seronegative prior to 3V, 149 (55.6%) seroconverted after the 3V dose and 119 (44.4%) did not. Conclusion: This study focuses on an important subset of patients with HM who are not seroconverting after the COVID mRNA 3V. This gain in scientific knowledge is needed for clinicians to target and counsel these vulnerable patients.

Real-World Third COVID-19 Vaccine Dosing and Antibody Response in Patients With Hematologic Malignancies

Purpose This study sought to describe the changes in immune response to a third dose of either Pfizer’s or Moderna’s COVID-19 mRNA vaccine (3V) among patients with hematologic malignancies, as well as associated characteristics. Methods This retrospective cohort study analyzed pre-3V and post-3V data on 493 patients diagnosed with hematologic malignancies across a large Midwestern health system between August 28, 2021, and November 1, 2021. For antibody testing, S1 spike antigen of the SARS-CoV-2 virus titer was used to determine serostatus. Results Among 493 participants, 274 (55.6%) were seropositive both pre- and post-3V (+/+) while 115 (23.3%) seroconverted to positive from prior negative following the third dose (−/+). The remaining 104 (21.1%) were seronegative both before and after 3V (−/−). No participant was seropositive pre-3V and seronegative post-3V (+/−). Results showed a statistically significant increase in the proportion of seropositivity after receiving a third COVID-19 vaccine (P<0.00001). Response to 3V was significantly associated with the 3V vaccine type (P=0.0006), previous COVID-19 infection (P=0.0453), and malignancy diagnosis (P<0.0001). Likelihood of seroconversion (−/+) after 3V was higher in the group of patients with multiple myeloma or related disorders compared to patients with lymphoid leukemias (odds ratio: 8.22, 95% CI: 2.12–31.79;P=0.0008). Conclusions A third COVID-19 vaccination is effective in producing measurable seroconversion in many patients with hematologic malignancies. Oncologists should actively encourage all their patients, especially those with multiple myeloma, to receive a 3V, given the high likelihood of seroconversion.