Characteristics of Patients with Hematologic Malignancies Without Seroconversion Post-COVID19 Third Vaccine Dosing

ABSTRACT

Patients with hematologic malignancies (HM) are at greater risk of severe morbidity and mortality caused by COVID19 and show a lower response to a two-dose COVID19 mRNA vaccine series. The primary objective of this retrospective cohort study is to explore the characteristics of the subset of patients with HM who had little to no change in SARS-CoV-2 spike antibody titer levels after a 3rd vaccine dose (3V) (-/-). As a secondary objective, we seek to compare the cohorts of patients who did and did not seroconvert post-3V to get a better understanding of the demographics and potential drivers of serostatus. A total of 625 patients with HM had two titer results at least 21 days apart pre- and post- the 3V dose. Among the participants who were seronegative prior to 3V (268), 149 (55.6%) seroconverted after the 3V dose and 119 (44.4%) did not. HM diagnosis was significantly associated with seroconversion status (P = .0003) with patients non-Hodgkin lymphoma 6 times the odds of not seroconverting compared to multiple myeloma patients (P = .0010). Among the cohort of patients who remained seronegative post-3V, 107 (90.0%) patients showed no reaction to 3V as indicated by pre- and post- 3V index values. This study focuses on an important subset of patients with HM who are not seroconverting after the COVID mRNA 3V, providing much needed data for clinicians to target and counsel this subset of patients.