A Multi-Provincial Clinical Evaluation of the PANBIO™ COVID-19 Antigen Rapid Test Device in South Africa.

Background: Rapid antigen tests were widely utilised during the COVID-19 pandemic to expand diagnostic access in resource-limited settings. However, prospective evaluations under intended-use conditions remained essential to define their role in decentralised testing strategies. Methods: We conducted a prospective multi-provincial clinical evaluation of the Panbio™ COVID-19 Antigen Rapid Test Device in South Africa between July 2021 and January 2022. Paired nasal and nasopharyngeal swabs were collected from 609 participants across three geographically diverse South African provinces. Antigen test results were compared with standard-of-care TaqPath RT-PCR, with BD MAX™ RT-PCR included as a secondary molecular comparator. Performance was assessed by viral load, symptom status, and variant predominance periods. Results: Standard-of-care RT-PCR identified 136 positive cases (22.3% prevalence). The Panbio™ test demonstrated overall sensitivity of 80.1% (95% CI: 72-87) and specificity of 98.5% (95% CI: 97-99). Sensitivity reached 90.1% in specimens with Ct values ≤25 and 85.2% among symptomatic participants tested within seven days of onset but declined at Ct values ≥30 and in asymptomatic individuals. Performance remained consistent during Delta- and Omicron-predominant periods. Discussion: The Panbio™ RDT demonstrates high diagnostic accuracy for detecting SARS-CoV-2 in individuals with high viral load, supporting its use for rapid identification of infectious cases during transmission surges. Molecular testing remains necessary for low viral load infections and asymptomatic screening.