B-054 Performance Evaluation of the VITROS HIV Combo Assay on the Ortho VITROS 3600 system

Abstract Background n 2014, the US CDC updated HIV screening algorithm, recommended any assay capable of reliably detecting p24 antigen and both IgG The HIV negative samples were confirmed based on a comprehensive assessment of HIV antibodies, HIV-1 p24 antigen, HIV nucleic acid testing, and follow-up testing results, and window period has been ruled out. Ten linear and sensitivity reference samples were added to the HIV-1 p24 antigen national reference material (batch number 20190505, purchased from the China Academy of Food and Drug Control) . The antigen concentrations from L1 to L10 were 20, 10, 5, 2.5, 1.25, 0.625, 0.313, 0.156, 0.0781, and 0 IU/ml, respectively. Results The sensitivity for this positive population of samples in the VITROS Combo test was calculated as 100.00% (164/164) with an exact 95% confidence interval (Cl) of 99.26% to 100.00%. The specificity for this negative population was 99.58% (Cl 99.38%-99.73%). Conclusions The sensitivity and specificity of VITROS Combo assay are very high. With class leading antigen sensitivity doesn’t sacrifice specificity. This new assay delivers excellent confidence in results, and with more target (HIV-1 p24) being detected, can helps laboratory shortening HIV infection window, improve operators and technicians’ confidence in the outcome of HIV testing.