In conversation with Ravi Sinha, Country Director, Ortho Clinical Diagnostics

- Tell us about CE-Marked VITROS® SARS-CoV-2 Antigen Test? How does this test work?

The CE-Mark VITROS® SARS-COV-2 antigen is a CLIA based high throughput laboratory test, that has been validated and approved by ICMR. It can detect SARS-CoV-2 infection in symptomatic individuals, in addition to asymptomatic individuals. The VITROS® antigen test can run up to 130 tests per hour and is a viable choice for frequent, high-throughput testing and monitoring of large community populations, including health care workers, schools, sporting organizations, manufacturing facilities, assisted and institutionalized living, and other communities with access to VITROS® instruments.

The VITROS® SARS-CoV-2 Antigen test uses respiratory specimens, that can be collected in bulk, and stored at room temperature for up to 24 hours or 48 hours if refrigerated. Contrary to PCR tests, which can take hours to obtain results, Ortho’s COVID-19 antigen test takes <50 minutes for its first result. Ortho’s SARS-CoV-2 antigen test runs on Ortho’s VITROS® XT 7600 Integrated System, the VITROS® 3600 Immunodiagnostic System, and the VITROS® 5600 Integrated System are self-contained and do not require an external water source to run, making them suitable for myriad locations that may not have accessible plumbing.

The VITROS® SARS-CoV-2 Antigen test detects the SARS-CoV-2 nucleocapsid antigen and uses an immunometric technique, which involves a two-stage reaction. In the first stage SARS-CoV-2 nucleocapsid antigen present in the sample binds with kit monoclonal anti-SARS-CoV-2 antibodies. In the second stage horseradish peroxidase (HRP)-labeled monoclonal anti-SARS-CoV-2 antibodies specifically binds to nucleocapsid antigen captured in the first stage. Final reading is taken using Chemiluminescent agent to produce light. Test results are expressed as S/Co (Signal to cutoff) numerical values will increase as the amount of SARS-CoV-2 antigen present in the sample increases.

- When did you launch CE-Marked VITROS® SARS-CoV-2 Antigen Test in India?

Ortho Clinical Diagnostics, India launched the CE-Marked VITROS® SARS-CoV-2 Antigen, in March 2021.

- Is it authorized by CDSCO?

VITROS SARS-CoV-2 Antigen test is validated by ICMR and approved by Central Drugs Standard Control Organization (CDSCO) for marketing in India.

- What are the parameters of this test?

The VITROS® SARS-CoV-2 Antigen test detects the SARS-CoV-2 nucleocapsid antigen in respiratory (Nasopharyngeal) specimens of symptomatic individuals and in Mid-turbinate specimen of asymptomatic individuals. Sample results will be displayed with a numerical signal to cutoff (S/C) value and a “Non-reactive” (negative) when S/C < 1.00 or “Reactive” (positive) label, when S/C >1.00. S/C value will increase as the amount of SARS-CoV-2 antigen present in the sample increases.

- How instant and accurate is this kit?

The VITROS® antigen test can run up to 130 tests per hour, with only 48 minutes for the first result. The results can continue to deliver, while new samples can be simultaneously loaded for testing. This on-demand, random access testing is very helpful for triaging hospital patients in COVID or Non-COVID wards.

The VITROS® SARS-CoV-2 Antigen test offers 100% PPA for all symptomatic patients between days 1-5 of symptoms onset. It also offers 100% PPA all symptomatic patients with CT (Cycle Threshold) <32. It also offers 92.3% PPA for all asymptomatic patients with CT (Cycle Threshold) <30. Samples with CT values of 30 or greater are less likely to contain live virus that are capable of replicating in cell cultures, suggesting less infectivity.