Performance evaluation of four kits for the detection of neutralizing antibody against SARS-CoV-2 in human serum

To evaluate four novel SARS-CoV-2 neutralizing antibody assay kits' application in neutralizing antibodies of population. Questionnaires from the voluntary participating researchers and selected the qualified questionnaires to analyse. For negative and positive coincidence rate, four novel SARS-Cov-2 neutralization antibody assay kits were tested. For within-run and between-run Precision verification study, four serum samples with two high and two low titer neutralizing antibodies were used to analyse. Based on the questionnaires, 175 qualified samples were divided into two groups. (1) negative neutralizing antibodies group: 31 samples had not been infected with the novel SARS-Cov-2 nor received the vaccine within the past one year; (2) positive neutralizing antibodies group: 144 samples were infected by COVID-19. There was 28 negative and 3 positive neutralizing antibodies of the individuals among the 31 negative samples which based on the questionnaires. The negative rates of 28 negative individules tested by GenScript, Vazyme and Hygeianey were 82.14 %, 60.71 % and 17.85 %, while the positive rates of the 147 positive samples were 93.87 %, 95.23 % and 100 %. The within-run coefficient of variations (C·V) of PBNAs, GenScript, Vazyme and Hygeianey were 11.49 %, 9.12 %, 7.97 % and 7.48 %, while the between-run coefficient of variations (C·V) were 21.37 %, 14.21 %, 12.29 % and 11.78 %. Due to the large within-run and between-run coefficient of variations, PBNAs was not suitable for large-scale promotion, while ELISAs could be leveraged for routine monitoring the titer of neutralizing antibodies against SARS-CoV-2.