Performance characteristics of the boson rapid SARS-cov-2 antigen test card vs RT-PCR: Cross-reactivity and emerging variants.

Background: SARS-CoV-2 virus has undergone several mutations on its genome, since the onset of the pandemic. Multiple variants of concern (VOC) have emerged including Alpha, Beta, Gamma, and Delta with the more recent one being the Omicron (B.1.1.529). Specific rapid antigen tests (RADs) have been used for the detection of SARS-CoV-2. However, since the emergence of new VOCs, the performance characteristics of these RADs needs to be re-evaluated. Objectives: The main purposes of this clinical study were to determine the diagnostic sensitivity and specificity of the BOSON Rapid Antigen Test compared to the gold standard real time RT-PCR and to determine the ability of the RAD to accurately depict different VOC. Additionally, the cross reactivity to other viruses and pathogen, as well as, the possible interference of non Covid-19 hospitalized patients for various causes, were investigated. Results: A total of 623 individuals (symptomatic) were tested. The sensitivity, specificity and accuracy of the BOSON RAD was 95.27%, 100% and 98.45% (n = 448), meeting the WHO recommended standards. Additionally, the Delta (83.33%, Ct < 34) and Omicron (100%, Ct < 26) VOC were determined with high sensitivity. Also, there was no interference from hospitalized, non-Covid 19 patients, and no cross-reactivity was detected. Conclusions: The study showed that this RAD could rapidly identify individuals with SARS-CoV-2, including those with the new dominant Omicron VOC, with no cross reactivity from other pathogens.