Characteristics of patients with hematologic malignancies without seroconversion post-COVID19 third vaccine dosing (3V): Real-world data from large midwestern healthcare system.
e19513 Background: Patients (Pts) with hematologic malignancies (HM) are at greater risk of severe morbidity and mortality caused by COVID19 and show a lower response to the two-dose COVID19 mRNA vaccine series. The primary vaccine series now includes a third dose of the COVID19 vaccine (3V) for immunocompromised Pts. The objective of this study was to explore the characteristics of HM patients who had no change in SARS-CoV-2 spike protein titer levels post 3V (-/-) to gain a better understanding of the drivers of serostatus. Methods: This retrospective cohort study analyzed Pt data on SARS-CoV-2 spike IgG antibody titers pre- and post- 3V across the healthcare system. This study included 268 fully vaccinated HM Pts diagnosed with HM between October 31, 2019 and January 31, 2022 and had a negative serostatus prior to 3V. Post 3V titers were obtained 21 days after 3V. Demographics, association between characteristics and seroconversion status, and odds ratios were all assessed (table).