Applicability evaluation of different ELISA kits for SARS-CoV-2 antibody screening of post-immunization plasma / 中国生物制品学杂志

ABSTRACT

SARS-CoV-2;ELISA-IgG;Neutralizing antibody;Dilution multiple;Post-immunization plasma;Qualified rate of plasma collection@#Objective To determine the optimal plasma screening kit for raw materials by comparing the qualified rate of plasma collection and operation convenience of four SARS-CoV-2 ELISA-IgG and neutralizing antibody kits from three manufacturers.MethodsSingle plasma samples with different ELISA dilution multiples screened from existing plasma immunized with SARS-CoV-2 vaccine were used as raw materials,which were detected by using SARS-CoV-2 ELISA-IgG and neutralizing antibody kits from different manufacturers. Plasma samples were mixed according to the potency level of each manufacturer,and pseudovirus neutralization test was carried out on pooled plasma. According to the potency of neutralizing antibody,the plasma collection standard of different kits were determined,and the qualified rate of plasma collection was calculated respectively. The dilution method of single plasma sample screening was determined in regard of the plasma collection standard,and the operation convenience was compared;The applicability of the kits were evaluated comprehensively.ResultsThe qualified rate of ELISA-IgG antibody kit of manufacturer B in 1 108 WT > 16 plasma samples was 82. 1% with internal control reference B2 as the plasma collection standard,which was higher than that of the current ELISA-IgG antibody kit of manufacturer A(59. 8%). With the level of 50 IU/mL tested by neutralizing antibody kit of manufacturer B as the standard of plasma collection,the qualified rate of plasma collection of this kit in 387 WT16 ～64 samples was 66. 4%,higher than that of ELISA-IgG kit of manufacturer A(42. 1%). While with the level of 100 IU/mL tested by neutralizing antibody kit of manufacturer C as the standard of plasma collection,the qualified rate of plasma collection of this kit in 536 WT16 ～ 64 samples was 42. 5%,lower than that of ELISA-IgG kit of manufacturer A(50. 2%).Neutralizing antibody kit of manufacturer C had the most operation steps and the longest reaction time;ELISA-IgG kit of manufacturer B had the shortest reaction time,and required no out-of-hole dilution for samples of WT16 ～ 64,while the ELISA-IgG kit of manufacturer A required out-of-hole dilution in transition plate. The difference of qualified rate of plasma collection among the four kits mainly occurred in the samples of WT16 ～ 64. The order of the qualified rate of plasma collection in this range wasELISA-IgG kit of manufacturer B > neutralizing antibody kit of manufacturer B > ELISA-IgG kit of manufacturer A > neutralizing antibody kit of manufacturer C. The order of operation convenience wasELISA-IgG kit of manufacturer B > neutralizing antibody kit of manufacturer B > ELISA-IgG kit of manufacturer A > neutralizing antibody kit of manufacturer C.ConclusionIn view of the overall analysis of the applicability from qualified rate of plasma collection and operation convenience,ELISA-IgG kit of manufacturer B is the optimal.