Seroconversion and outcomes after initial and booster COVID-19 vaccination in adults with hematologic malignancies.

BACKGROUND: Patients with hematologic malignancies have impaired humoral immunity secondary to their malignancy and its treatment, placing them at risk of severe coronavirus disease-19 (COVID-19) infection and reduced response to vaccination. METHODS: The authors retrospectively analyzed serologic responses to initial and booster COVID-19 vaccination in 378 patients with hematologic malignancy and subsequently tracked COVID-19-related outcomes. RESULTS: Seroconversion occurred in 181 patients (48%) after initial vaccination; patients who had active malignancy or those who were recently treated with a B-cell-depleting monoclonal antibody had the lowest rates of seroconversion. For initial nonresponders to vaccination, seroconversion after a booster dose occurred in 48 of 85 patients (56%). The seroconversion rate after the booster was similar for patients on (53%) and off (58%) active therapy (p = .82). Thirty-three patients (8.8%) developed a COVID-19 infection, and there were three COVID-19-related deaths (0.8%). Although no significant association was observed between postvaccination seroconversion and the incidence of COVID-19 infection, no patient with seroconversion died from COVID-19, and no patient who received tixagevimab/cilgavimab (N = 25) was diagnosed with a COVID-19 infection. CONCLUSIONS: Booster vaccinations can promote seroconversion in a significant proportion of patients who are seronegative after the initial vaccination course regardless of the specific vaccine or on/off treatment status at the time of revaccination. Although postvaccination seroconversion may not be associated with a decrease in any (including asymptomatic) COVID-19 infection, the authors' experience suggested that effective vaccination (including a booster), supplemented by passive immunization using tixagevimab/cilgavimab in case of lack of seroconversion, effectively eliminated the risk of COVID-19 death in the otherwise high-risk population. LAY SUMMARY: Patients with hematologic malignancy, especially lymphoma, have an impaired response to coronavirus disease 2019 (COVID-19) vaccination. In this single-institution review, less than one half of the patients studied made detectable antibodies. For those who did not make detectable antibodies after initial vaccination, over one half (65%) were able to produce antibodies after booster vaccination. By the end of February 2022, 33 of the original 378 patients had a documented COVID-19 infection. The only deaths from COVID-19 were in those who had undetectable antibodies, and no patient who received prophylactic antibody therapy developed a COVID-19 infection.

Validation and performance comparison of three SARS-CoV-2 antibody assays.

Serology testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly being used during the current pandemic of coronavirus disease 2019 (COVID-19), although its clinical and epidemiologic utilities are still debatable. Characterizing these assays provides scientific basis to best use them. The current study assessed one chemiluminescent assay (Abbott COVID-2 IgG) and two lateral flow assays (STANDARD Q [SQ] IgM/IgG Duo and Wondfo total antibody test) using 113 blood samples from 71 PCR-confirmed COVID-19 hospitalized patients, 119 samples with potential cross-reactions, and 1068 negative controls including 942 pre-pandemic samples. SARS-CoV-2 IgM antibodies became detectable 3-4 days post-symptom onset using SQ IgM test and IgG antibodies were first detected 5-6 days post-onset using SQ IgG. Abbott IgG and Wondfo Total were able to detect antibodies 7 to 8 days post-onset. After 14 days post-symptom onset, the SQ IgG, Abbott IgG and Wondfo Total tests were able to detect antibodies from 100% of the PCR-confirmed patients in this series; 87.5% sensitivity for SQ IgM. Overall agreement was 88.5% between SQ IgM/IgG and Wondfo Total and 94.6% between SQ IgG and Abbott IgG. No cross-reaction due to recent sera with three of the endemic coronaviruses was observed. Viral hepatitis and autoimmune samples were the main source of limited cross-reactions. The specificities were 100% for SQ IgG and Wondfo Total, 99.62% for Abbott IgG, and 98.87% for SQ IgM. These findings demonstrated high sensitivity and specificity of appropriately validated SARS-CoV-2 serologic assays with implications for clinical use and epidemiological seroprevalence studies.

Evaluation of BioPlex 2200 Syphilis Total With Automated Rapid Plasma Reagin: Experience From a Tertiary Medical Center.

BACKGROUND: Treponema-specific assays are widely adopted in the first step of the reverse algorithm of serologic syphilis screening. The new BioPlex 2200 Syphilis Total and rapid plasma reagin (RPR) test is designed to perform the first 2 steps of the algorithm simultaneously. However, limited data regarding the BioPlex Syphilis Total and RPR in clinical practice exist. METHODS: A total of 293 random samples at a tertiary medical center were tested by BioPlex Syphilis Total and RPR, BioPlex Syphilis IgG, Architect Syphilis TP, and BD Macro-Vue RPR card. Treponema pallidum particle agglutination (TP-PA) assay and clinical chart review were used to resolve discrepancies. Comparisons were performed among treponemal-specific assays and between 2 RPR tests. RESULTS: Good overall agreements (>91%) were achieved between BioPlex Syphilis Total, BioPlex Syphilis IgG, and Architect Syphilis TP. Overall agreement between BioPlex RPR and BD RPR was 86.8% with positive percent agreement of 66.7% and negative percent agreement of 96.3%. There were 37 discordant samples including 30 with BD RPR+/BioPlex RPR- and 7 with BD RPR-/BioPlex RPR+. Negative BioPlex RPR results were observed in samples with reactive BD RPR: 10 (91%) of 11 for BD RPR 1:1, 13 (65%) of 20 for BD RPR 1:2, 6 (35%) of 17 for BD RPR 1:4, and 1 (7%) of 14 for BD RPR 1:8. The discordant samples were predominantly from patients with high-risk of syphilis reinfection and included 9 patients with an early reinfection. CONCLUSIONS: Our results demonstrated that BioPlex Syphilis Total and Architect Syphilis TP performed similarly. The BioPlex RPR missed a small number of early syphilis reinfections, and its implementation should depend on the patient population that the laboratory serves.