Coronavirus: ELISA COVID-19 kit could alter testing landscape

The RT-PCR test may be the gold standard of testing for COVID-19, but a new ELISA antibody testing kit designed by the Biocon’s research arm, Syngene, could potentially alter just how the state carries out testing in the future.

While the RT-PCR method takes up to eight hours to deliver results on nasal samples, ELISA (Enzyme-Linked Immunoassay) kits can deliver results from one to three hours.

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The test works by sampling collected material from COVID-19 test subjects for the presence of Sars-Cov-2 antibodies, primarily Immunoglobulins G and M. This would, in turn, confirm that the test subject had been exposed to the virus. Immunoglobulin G (IgG) is the most common type of antibody.

For virologists and epidemiologists, the advantage of ELISA technology is that it will help identify the scale of the subclinical infection (or early-stage or mild infection) within the general population.

“Some 80% of all COVID-19 infections are subclinical. What IgG antibody testing will help with is in identifying and certifying protected individuals who are no longer susceptible to infection. Since they pose no risk to others, they can be free to rebuild all locked-down socioeconomic functions,” said Dr T Jacob John, a noted virologist who formerly headed ICMR’s Centre for Advanced Research in Virology.

Dr John has been critical of testing programmes in India for only testing for the virus and not antibodies. He told DH that there is no sense of gauging the true scale of subclinical infection in the general population until we test everyone for IgGs.

Meantime, the Bengaluru-based Centre for Cellular and Molecular Platforms (C-Camp), Department of Biotechnology, described the development of the new kits as timely.

Syngene is a member of the National Biomedical Resources Indigenization Consortium (NBRIC), which was hosted and convened by C-Camp.

“Most of these antibody kits were hitherto being imported. But supply chains worldwide are seriously hampered and diverted and grave misgivings have recently surfaced about quality and the efficacy of these imported kits,” C-Camp said in a statement.

A spokesperson for C-Camp added that the kits will be sent to National Institute of Virology, Pune, for validation.

She added that the development comes at an “extremely opportune time” when the Indian Council for Medical Research (ICMR) has widened testing protocol to survey for community exposure especially among vulnerable groups through rapid ELISA tests.

Syngene has tied up with HiMedia Laboratories to manufacture and distribute the kits.