Abstract
Levels of neutralizing antibodies (NAb) after vaccine against coronavirus disease 2019 (COVID-19) can be detected using a variety of methods. A critical challenge is how to apply simple and accurate methods to assess vaccine effect. In a population inoculated with three doses of the inactivated Sinopharm/BBIBP vaccine, we assessed the performance of chemiluminescent immunoassay (CLIA) in its implementation to detect severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) specific antibodies, as well as the antibody kinetics of healthcare workers throughout the course of vaccination. The antibody levels of NAb, the receptor-binding-domain (RBD) antibodies and IgG peaked one month after the second and remained at a relatively high level for over three months after the booster injection, while IgM and IgA levels remained consistently low throughout the course of vaccination. The production of high-level neutralizing antibodies is more likely when the inoculation interval between the first two doses is within the range of one to two months, and that between the first and booster dose is within 230 days. CLIA showed excellent consistency and correlation between NAb, RBD, and IgG antibodies with the cytopathic effect (CPE) conventional virus neutralization test (VNT). Receiver operating characteristic (ROC) analysis revealed that the optimal cut-off levels of NAb, RBD and IgG were 61.77 AU/ml, 37.86 AU/ml and 4.64 AU/ml, with sensitivity of 0.833, 0.796 and 0.944, and specificity of 0.768, 0.750 and 0.625, respectively, which can be utilized as reliable indicators of COVID-19 vaccination immunity detection.
Keywords: antibody persistence; booster; chemiluminescent immunoassay; coronavirus disease 2019; vaccine.
【저자키워드】 Coronavirus disease 2019, Vaccine, chemiluminescent immunoassay, antibody persistence, booster, 【초록키워드】 COVID-19, coronavirus disease, neutralizing antibody, CLIA, SARS-CoV-2, IgG, IgM, Coronavirus disease 2019, Vaccine, coronavirus, vaccination, Healthcare workers, Immunity, Neutralizing antibodies, antibody, severe acute respiratory syndrome coronavirus-2, severe acute respiratory syndrome Coronavirus, healthcare worker, Severe acute respiratory syndrome, sensitivity, specificity, IgG antibody, ROC, COVID-19 vaccination, IgG antibodies, RBD, antibody kinetics, virus neutralization test, neutralization test, implementation, antibody levels, receptor, chemiluminescent immunoassay, respiratory, correlation, Critical, booster dose, inactivated, specific antibodies, Sinopharm, Coronavirus-2, CPE, Cytopathic effect, Analysis, dose, receiver operating characteristic, acute respiratory syndrome, booster injection, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus-2, injection, cut-off, IgA levels, conventional virus neutralization test, VNT, Course, detect, inoculated, peaked, remained, variety, Level, IgA level, 【제목키워드】 inoculation, investigation, Level,