Observational Study of Receptor Binding Domain Spike Antibody Responses to 3 SARS-CoV-2 Vaccinations in Noninfected Subjects: Parallel Neutralizing Antibody and Cardiac Troponin I and T Observations.

BACKGROUND: Our goals were to demonstrate receptor binding domain spike 1 (RBD S1) protein antibody (Ab) kinetic responses to multiple vaccines over approximately 180 days, neutralizing Ab effectiveness, and high-sensitivity cardiac troponin I (hs-cTnI) and T (hs-cTnT) responses in postvaccinated, non-SARS-CoV-2-infected subjects. METHODS: Blood specimens were collected pre- and postvaccinations from seronegative subjects. RDB S1 Abs were measured by the novel Qorvo Biotechnologies Omnia platform. Neutralizing Abs and hs-cTnI and hs-cTnT were measured on the ET Healthcare Pylon 3D. RESULTS: Two-dose vaccines (Pfizer, Moderna) had peak RBD S1 Ab concentrations about 45 to 55 days after both doses and showed declines over the next 50 to 70 days. The Janssen vaccine showed lower RBD S1 Ab peak concentrations, continued to increase over time, and plateaued after 60 days. There was strong neutralizing Ab response post vaccinations, with only 3 specimens, shortly before and shortly after vaccination, not showing a response. Specimens showed no hs-cTnI (all < 3 ng/L) and hs-cTnT (all < 6 ng/L) increases or changes over time. CONCLUSIONS: We demonstrate in seronegative SARS-CoV-2 subjects that Pfizer and Moderna vaccinations provide strong, neutralizing RBD S1 Ab effectiveness, based on 2 different assays after 2 doses, with the Janssen single-dose vaccine showing a lower RBD S1 Ab response over 4 to 6 months. No myocardial injury was associated with the Pfizer postvaccination. The Qorvo Biotechnologies RBD S1 Ab assay measured on the Omnia platform has potential as a point-of-care platform.

Evaluation of two point of care technologies for measuring monoclonal antibody therapeutic-A concentrations in blood.

Aim: Current blood monitoring methods require sample collection and testing at a central lab, which can take days. Point of care (POC) devices with quick turnaround time can provide an alternative with faster results, allowing for real-time data leading to better treatment decisions for patients. Results/Methodology: An assay to measure monoclonal antibody therapeutic-A was developed on two POC devices. Data generated using 75 serum samples (65 clinical & ten spiked samples) show correlative results to the data generated using Gyrolab technology. Conclusion: This case study uses a monoclonal antibody therapeutic-A concentration assay as an example to demonstrate the potential of POC technologies as a viable alternative to central lab testing with quick results allowing for real-time decision-making.