Background: This study compared the neutralizing antibody kit using the Enzyme-Linked Immunosorbent Assay (ELISA) method with the rapid antibody diagnostic kit using the Lateral Flow Immunoassay (LFIA) method to evaluate the clinical effectiveness of the COVID-19 Biokit IgG/IgM regarding evaluation of antibody formation after COVID-19 vaccination. Methods: The neutralizing antibody test was performed with antibody detection kit of diagnostic medical devices for the qualitative method using the standard ELISA method. The rapid antibody diagnostic kit was measured with the COVID-19 Biokit IgG/IgM using the LFIA method. Based on the results of the neutralizing antibody measurement test of the standard test method, the test results of the rapid antibody diagnostic kit are compared and analyzed to confirm its the sensitivity and specificity. Results: When the consistency was determined as positive and negative for the two test results, 118 cases were matched and two cases were inconsistent, showing a 98.3% consistency rate. That is, sensitivity 98%, specificity 100% and correctly classified proportion 98%. Conclusions Although the positive results of antibody formation of this kit would mean that individual has immunity to COVID-19, the result cannot be used to confirm or evaluate for re-infection. But the strong agreement between rapid antibody diagnostic kit results and ELISA results suggests that the kit used in this study is available as a screening test for antibody and neutralizing antibody responses, which could help evaluate the need for additional vaccinations, collect data quickly and cheaply and monitor individual immune responses.