India’s home-grown testing kit OmiSure, developed by the Tata Medical and Diagnostics (Tata MD) to identify the Omicron variant of Covid-19 in samples taken from the nose and throat, was approved by the Indian Council of Medical Research (ICMR) Wednesday and will be available for commercial use from January 12.
Apart from identifying the B.1.1.529 (Omicron) variant, the kit can also detect any other circulating SARS-CoV-2 variant.
The company said the unique test design developed by scientists at Tata MD is a single tube, fully multiplexed test (provisional patent application filed). Therefore, it has two checks in place for Omicron detection without compromising the ability to detect other SARS-CoV-2 variants.
The kit evaluated in partnership with the ICMR reported 100 per cent sensitivity and 99.25 per cent specificity for detection of variants of SARS-CoV-2, including Omicron.
OmiSure is the first test to use a combination of two S-gene viral targets to identify Omicron. The first target is based on S-gene dropout or S-gene target failure (SGTF) and the second target is based on S-gene mutation amplification (SGMA).
The company said that they have begun working to scale up the production capability, supply chain and raw material inventory to deliver two lakh OmiSure tests per day.
“It can help cut half the cost and complexity of first-line Covid-19 testing and Omicron screening. Most states have adopted a dual-testing strategy at the point of first-line testing, where samples are first tested with cost-effective regular Covid-19 RT-PCR tests and then, positive samples are screened for Omicron with a more expensive SGTF assay and prioritised for sequencing,” the company said.
The kit developed by a team headed by Bengaluru-based Dr V Ravi, former head of neurovirology, NIMHANS, and currently head of R&D, Tata MD, is listed on the ICMR website as the only kit approved specifically for Omicron detection.
Speaking with The Indian Express, Ravi said, “It is not a home testing kit. There are a lot of misconceptions. OmiSure is not a self-test kit. It detects viral genetic material and not viral antigen. It is not a Rapid Antigen Test (RAT). Polymerase Chain Reaction (PCR) can only be done in laboratories. It requires special equipment, trained people and a certain amount of bio-safety. PCR has been done right from the beginning of the pandemic. OmiSure is a real-time PCR so it is not available for public use at home.”
“I started working on the development of the kit just a couple of days after Omicron was announced, which was roughly by the end of November 2021. Right after the first case of Omicron was reported, we had submitted the kit for an ICMR evaluation. This is the fastest-developed kit globally. From the specimen collection to the reporting like other PCRs, the kit takes a maximum two and a half hours to give the results. Moreover, there are plans to export the kit as globally it has an advantage of being able to screen S-gene dropout as well as specific detection,” Ravi explained.
Ravi, who is also the nodal officer and chairman of the Covid-19 whole genome sequencing committee in Karnataka, said Omicron has swept Mumbai and Delhi and has more or less replaced the Delta variant. “It will happen across the country,” he stated.
“I have learnt one thing from the pandemic about this virus that is not to give assurances. Yes, most of the people seem to be getting mild infections but that does not mean we should brush it aside saying it is not going to cause any problem because most people getting infected are already vaccinated with either one dose or two doses. We still do not have data on people who have not been vaccinated whether the infection is mild, moderate or severe. I would tread with caution and would advise people to wear masks and avoid crowds so that they do not get infected. Nobody wants to get infected. Our target should be no infection,” he said.