Changes in serum antibody titers after vaccination for COVID-19 and evaluation of post-vaccination health conditions

　Introduction: The coronavirus disease 2019 (COVID-19) vaccine has preventive effects and high immunogenicity, but the outcomes of vaccination have not been widely reported. The goal of this study was to examine serum antibody titers before and after vaccination and to evaluate post-vaccination health conditions.　Methods: The subjects were 2,304 medical workers (mean age 41 years) at Kawasaki Gakuen who agreed to participate in the study and underwent COVID-19 vaccination, beginning in March 2021. Serum IgG antibody titers for SARS-CoV-2 spike protein were measured before the first vaccination and 4 weeks after the second vaccination. Health conditions were observed for 4 weeks after the second vaccination.　Results: The rates of seroconversion, seroprotection, and change in geometric mean antibody titer at 4 weeks after the second vaccination were 99.9%, 99.9%, and 2,685.5 (95% CI 587.8-5,319.2), respectively, suggesting high immunogenicity. After the first vaccination, pain, enlargement, and reddening occurred at the local injection site, and systemic side effects included fatigue, headache, physical pain, chill, nausea, and fever. After the second vaccination, the incidence of pain decreased, but those of other events increased. There were no serious side effects requiring hospitalization. In logistic regression analysis, sex, age, fever,chill, and lymph node enlargement after the second vaccination were associated with a change in antibody titer.　Conclusions: Serum antibody titers suggested high immunogenicity of the COVID-19 vaccine and a health condition survey confirmed the safety of the vaccine. Systemic side effects may serve as an index of immunization (acquisition of antibody) by the vaccine

Post-induction MRD by FCM and GATA1-PCR are significant prognostic factors for myeloid leukemia of Down syndrome.

Myeloid leukemia of Down syndrome (ML-DS) is associated with good response to chemotherapy, resulting in favorable outcomes. However, no universal prognostic factors have been identified to date. To clarify a subgroup with high risk of relapse, the role of minimal residual disease (MRD) was explored in the AML-D11 trial by the Japanese Pediatric Leukemia/Lymphoma Study Group. MRD was prospectively evaluated at after induction therapy and at the end of all chemotherapy, using flow cytometry (FCM-MRD) and GATA1-targeted deep sequencing (GATA1-MRD). A total of 78 patients were eligible and 76 patients were stratified to the standard risk (SR) group by morphology. In SR patients, FCM-MRD and GATA1-MRD after induction were positive in 5/65 and 7/59 patients, respectively. Three-year event-free survival (EFS) and overall survival (OS) rates were 93.3% and 95.0% in the FCM-MRD-negative population, and 60.0% and 80.0% in the positive population. Three-year EFS and OS rates were both 96.2% in the GATA1-MRD-negative population, and 57.1% and 71.4% in the positive population. Adjusted hazard ratios for associations of FCM-MRD or GATA1-MRD with EFS were 10.98 (p = 0.01) and 27.68 (p < 0.01), respectively. Detection of MRD by either FCM or GATA1 after initial induction therapy represents a significant prognostic factor for predicting ML-DS relapse

Changes in serum antibody titers after vaccination for COVID-19 and evaluation of post-vaccination health conditions

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